- This article describes large animals. See pests for insects and other small animals.
Any large animal is capable of killing a human, and almost any small animal, from the size of a mouse, is capable of inflicting a nasty injury. Even apparently unlikely animals can be dangerous: a cute bunny has both claws and teeth, a large goose can be extremely nasty, and in 2014 a fisherman in Belarus died from a beaver bite when he tried to grab the animal to get a good photo.
Proverbially dangerous beasts include a cornered animal, males of some species in mating season, and a mother with offspring to protect. Even otherwise gentle domestic animals can be dangerous in some circumstances: a horse may kick if startled, a dog may snap if interrupted while feeding, and so on. Some species such as hyenas and wolverines have a reputation for being bad-tempered enough to attack more-or-less anything that comes in range.
Large predators, such as crocodiles, sharks and big cats, are obviously dangerous. However, very few animal species regard human beings as prey. More people are killed by large herbivores than by predators. In North America, moose attack more people than bears and wolves combined. Worldwide, hippos injure more people than any other animal, and moose rank second. In the water, jellyfish cause more injuries than sharks.
Most animals, large or small, can also be pests; stealing food, spreading infections, or damaging property.
|“||...release the tiger!||”|
—Monty Python, Self-defence against fruit
Wild animals are much more dangerous than domesticated ones. Getting too close to a cow is not very likely to get you gored or trampled, and most large dogs are unlikely to savage you. Trying the same behavior with a wild buffalo or a wolf, though, is almost certain to have serious repercussions. Animals that travel in groups are also much more dangerous; you might survive an encounter with one angry buffalo or wolf, but against a whole herd or pack your chances would be very slim indeed.
Few species will do you harm if you keep your distance, but the appropriate distance varies both with species and with circumstances. Unless you are an expert on the species in question, follow the general rule that if the animal's behavior changes at all (even turning its head to look at you), then back off immediately.
If you want to photograph wildlife, get a nice long telephoto lens so you can keep your distance and avoid disturbing the animals. This is much safer and it is also very likely to give better pictures.
Nearly all dangerous animals are far faster than most humans. Do not count on running away if it attacks, but stay far enough that it does not attack. This includes seemingly clumsy animals like hippos, bears, crocodiles and musk oxen, and small ones like snakes. They may not run far, but may reach much farther than you supposed. For some predators, turning your back and running away activates their hunting instinct, so controlling your nerves may be important.
Captive animals are no less dangerous than their wild relatives. Safari parks and zoos with the best handling practices have still had animal attacks on staff and visitors. Follow rules and staff instructions.
See also our article on pests, small animals able to annoy, infect or poison people.
See animal collisions for traffic accidents involving animals.
High-risk places, where wild animals are often seen:
- Streams and other bodies of water; especially in dry regions and seasons as water is scarce
- Farmlands, landfills and waste bins, where wild animals might look for food
- When you see one animal, others are probably nearby
Times and situations when animals might be aggressive:
- Mating season
- Protecting offspring
- Protecting killed prey
- Provoked by dogs
- Sunrise and sunset, when animals are on the move; also has a blinding effect
Alligators and crocodiles
Crocodiles do not hesitate to eat human beings who swim or wade in streams where they live, so make sure you know whether crocodiles are present before swimming in areas where they might be lurking.
While alligators are less aggressive toward humans in general than crocodiles, there have been many cases of predation or injury of human beings by alligators. In areas where alligators are common, avoid swimming in, or going dangerously close to, bodies of water where they may lurk.
Chimpanzees have been known to attack humans in the wild, and can cause serious injury or death. Gorillas are very strong and have in rare cases attacked humans, but they generally don't attack unless provoked, and will show warning signs before attacking.
Bear danger is the risk encountered by humans and their pets or livestock when interacting with bears. Bear danger is prevalent in most areas populated with bears. The European brown bear generally avoids humans, but can attack if cornered.
Polar bears have no reluctance in stalking and eating people; they survive mainly by hunting and humans are roughly the same size and shape as seals, which are among their usual prey. If you visit areas within the polar bear habitat, such as Churchill, in the Canadian Arctic, or Svalbard, you must take special precautions to avoid becoming prey. Consult local authorities before leaving settlements - carrying fire arms is often required in such areas. Warning: The polar bear is very fast; you cannot run away from a polar bear.
Other types of bears, such as black bears and grizzly bears, are versatile foragers rather than pure hunters; they are less likely to want to eat you and much more likely to want to eat your food. But regardless, they are big, extremely strong animals that can easily maul an adult human being to death, so be careful when you visit areas where they live. If you run into a black bear, you have a good chance of scaring him or her off by waving your hands and shouting, or by hitting or kicking it in the (rare) case that it attacks.
Before backpackers are allowed to enter an area with bears, they may be required to watch an instructional video on how to avoid encountering or agitating bears. If not, you can still ask for advice. Best strategies for dealing with bear danger differ from place to place.
In any area, making noise to avoid startling a bear and to prevent yourself from getting between a mother and her cubs will increase your safety. Many hikers wear special bear bells at their ankles to warn the bears of human presence. It is always safer to hike in noisy groups rather than solo. In some areas, food and scratches should be handled such that the bears cannot get at them, or at least do not come to you for them.
Dealing with bear encounters
Hanging food in a tree does not guarantee it will be safe, but any method other than counterbalancing will probably not protect it. Hang food only when storage boxes or bear-proof containers or panniers are not available. Find a tree with a live, down-sloping branch, even if you must select a different campsite. Divide food into two balanced bags. Store soap, sunscreen, deodorant, toothpaste and garbage in the same way as food. Bears are attracted to anything with an odor. Use enough rope to go over the branch and back to the ground. Toss it far out on the branch where it will support the weight of the food but not a bear cub. Make sure no objects are below the branch that could support a bear. Tie on and hoist the first sack up to the branch. Tie the second sack as high as you can on the rope; put the excess rope in the sack, leaving a loop out so you can retrieve it. Toss or use a stick to push the lower sack until both sacks are at equal height. To retrieve the sacks, hook a long stick through the loop of excess rope. Pull slowly to avoid tangles.
If you see a bear, back off slowly or keep your distance and make noise to avoid startling the bear. The best noise in this situation may be talking with a calm voice (which tells the bear you are human and that you have no aggressive intentions). If a bear becomes confrontational, either back off slowly or stand your ground, raise your arms above your head so as to appear larger and yell at the bear (advice differs). Never turn your back on the bear or run; running away can activate the hunting instincts of the bear and lead to it perceiving you as prey. Climbing a tree is also not the best idea, as black bears are good climbers and grizzlies have occasionally been known to climb trees as well.
If a bear does charge, you should muster your courage, as most bear charges are bluff. Either stand your ground or curl into a fetal position so as to shield vital organs and appear non-threatening. If the bear does attack, you can still curl into the fetal position. If this is not enough, you can either hope the bear will lose its interest without doing too much damage or fight the bear in any way you can.
There is also bear spray – a special form of pepper spray – available in some areas for additional protection. However be warned that bear spray is designed to make a large short blast that only lasts a few seconds so proximity to the bear is key. Most bear sprays come with a safety so make sure you understand how the safety works and wear your bear spray where it can easily be accessed in an emergency.
This advice applies to omnivores such as brown and black bears; the best way to avoid being attacked by the completely carnivorous polar bear is not to enter any area where polar bears live, remain inside a hard-shell vehicle or building, or at least have a guide trained to deal with the polar bears.
Food storage and garbage disposal
Bears are opportunistic omnivores with an excellent sense of smell, and are attracted to human and pet foods as well as refuse. Improper storage of these items can allow bears to eat human food and become dependent on it, increasing the probability of encounters with humans. Most brown and black bear encounters in populated areas involve so-called "trouble bears", usually young males who have just left their mothers and do not yet have a territory of their own. If they wander close to human settlements, the smells of cooking and garbage can cause them to ignore their usual instinct to avoid humans. Many parks and people in areas with bears utilize bear-resistant garbage cans and dumpsters for this reason, and many areas have laws prohibiting the feeding of bears, even unintentionally.
Campers can access bear-proof containers at many parks to store their food and trash and they may be required in some areas. The containers are then buried or strung on a rope between two tall trees, out of bears' reach. They are also instructed to put their containers, campfire, and tenting 100 meters away from each other, forming a triangle.
The largest birds, such as ostriches and emus, can kick down a human. The cassowary, found in Australia and New Guinea, has been known to deal fatal injuries to people and other animals, but is usually shy and avoids humans.
Some birds protect their nests or offspring quite aggressively. Some owls, notably the Ural owl, are especially nasty, as they often attack without any preceding fake attacks – and in total silence.
Gulls, informally referred to as "seagulls", were once primarily sea-going birds that nested on cliffs and in other wild places. Some time in the 1940s, however, some types of gull began to move increasingly into human settlements and nest there instead. It is not entirely known why this shift occurred, but as some gulls are opportunistic and adaptable feeders it is possible that they found easy food in newly-made landfill sites and on the street. Seeing a squad of gulls quickly hoover up a discarded doner kebab is something of a spectacle.
Two of the species that moved in next door to people, herring gulls and lesser black-backed gulls, are vigilant in defending their nests and young. Even if they've seen and lived next to humans every day of their lives, once their chicks hatch, everything and anything can be seen as a potential threat. These gulls are large and have sharp beaks and claws, and injuries occur often.
There is no way to prevent the gulls from attacking, and harming the gulls or their nests and young is illegal (in certain cases licences can be granted). Gulls can be discouraged from areas by removing readily-available food sources such as easily torn bin bags and stopping people from directly feeding the birds. Nesting can be discouraged by fitting specially-made spikes. All discouraging methods should be started early in the year before the birds start to breed.
Do not contribute to the problem by letting them get food from you. In some places tourists are a major source of food – offered, abandoned or taken from you.
Swooping season in Australia
Australian magpies (Cracticus tibicen) are a common bird found throughout Australia. In September and October, their mating season, they become extremely vigilant in defending their nests and young and will divebomb and peck anything they perceive as a threat - usually humans. Due to the sheer number of these birds, simply walking down a street can result in multiple attacks. As such, this time of year has colloquially become known among Australians as "swooping season".
There is no way to stop the magpies, but various techniques have been developed to prevent injury. Zipties tied to a bicycle helmet have proven effective, as have other hard plastic head coverings.
- Main article: Aggressive dogs
It is not just that dogs can be dangerous – in some countries where inadequate veterinary services are available, dogs can be rabid – a bite from them and you are in serious trouble.
Even friendly non-rabid dogs pose some danger. An otherwise gentle dog may snap if someone approaches when it is feeding, and a large dog may cause injury with overly enthusiastic friendly gestures such as jumping up on someone.
One thing about elephants making them dangerous is the fact that they are huge. You could get accidentally crushed, and one well placed kick of their foot or thrust of their tusks can easily kill you. On the other hand as they are herbivores, they are usually not aggressive per se. As with almost all animals a mother that perceives a threat to her child becomes unpredictable and will not even take care of her own safety until the (perceived) threat is gone.
Big cats such as tigers, lions, leopards, jaguars, panthers and pumas (aka cougars or mountain lions) have been known to kill people.
Smaller cats such as bobcat or lynx are extremely unlikely to see adult humans as prey, but are quite capable of doing serious injury in the highly improbable event that you manage to corner one.
Don’t hike alone. Make noise to avoid surprising a mountain lion and keep children close to you at all times. If you do encounter a mountain lion, do not run. Talk calmly and loudly, avert your gaze, stand tall, and back away. Unlike with bears, if attack seems imminent, act aggressively. Try to make yourself look bigger (for instance, raise your jacket above your head). Do not crouch and do not turn away. Mountain lions may be scared away by being struck with rocks or sticks, or by being kicked or hit. They are primarily nocturnal, but they have attacked in broad daylight. They rarely prey on humans, but such behavior occasionally does occur. Children and small adults are particularly vulnerable.
Hippopotamuses are extremely dangerous; even large crocodiles generally avoid them. The hippopotamus is semi-aquatic, inhabiting rivers, lakes and mangrove swamps, where territorial bulls preside over a stretch of river and groups of 5 to 30 females and young. During the day, they remain cool by staying in the water or mud then they emerge at dusk to graze on grass. While hippopotamuses rest near each other in the water, grazing is a solitary activity and hippos are not territorial on land. They are the third largest type of land mammal by weight (between 1½ and 3 tonnes): the only heavier species on average are the white and Indian rhinoceroses, typically 1½ to 3½ tonnes, and the elephants, typically weighing 3 to 9 tonnes. The hippopotamus is one of the largest quadrupeds and, despite its stocky shape and short legs, it can easily outrun a human. Hippos have been clocked at 30 km/h (19 mph) over short distances. The hippopotamus is one of the most aggressive creatures in the world and is regarded as one of the most dangerous animals in Africa.
Horses and ponies
See horse riding for a general discussion of the joys and hazards of horses and ponies. Falling off them is the most common danger, but there are other risks.
A bite from a horse or pony is serious and a kick can be fatal, but the risk of these is small with a well-trained horse or pony unless you startle or provoke it. Ask the owner before going close. Talk calmly to the animal, approach from the side, and show the horse or pony what you are going to do; avoid doing anything surprising. Also avoid going close behind a horse or pony as this is the direction in which they can kick most easily and is out of their field of view so movement there may startle them.
Having a horse accidentally step on your foot can also cause serious injury. The larger breeds can do more damage, but even a pony is heavy enough to hurt you quite badly.
Wild horses and ponies
Wild horses and ponies vary in how they perceive people. Some herds that are managed by people or closely associate with them may be more tolerant, but all wild animals should be seen as unpredictable no matter what. Avoid getting too close and definitely avoid feeding them - in some places this is illegal. You should also never get close to a stallion with mares or to mares with foals as they will be more defensive and therefore more likely to charge at you.
If you do find yourself close to a wild horse or pony then they will usually give warnings via body language before they charge. If a horse's ears go back then the animal is not happy and you should back off. If the ears are pinned back and there is also teeth-baring and hoof-stomping or head-tossing then you've really caused upset and should get out of there pronto! Upset horses and ponies may also turn so that they are facing away from you - that could mean they're getting ready to deliver a powerful kick with their hindlegs, so keep clear!
We have a separate article covering jellyfish. In Northern Australia - and specifically the Northern Territory - on the coast, beach swimming is strongly advised against due to the difficult to see and very dangerous forms of jellyfish.
General advice is not to touch any jellyfish, even ones that are dead on the shore, as they may still be able to deliver a sting.
- Main article: Pests
In some countries - biting insects are capable of inflicting serious illnesses, and in some cases life threatening conditions. It is well worth researching whether countries you are visiting have any warnings regarding dangerous insects. In some countries ant bites can create serious reactions. The malaria mosquito kills more people than any other animal. In tropical countries the risk of insect transferred diseases must be taken seriously.
If you enter an area where kangaroos live, give them as much space as possible. If you see one, stay away from it and watch how it behaves. If it moves toward you or shows signs of being aggressive, move away (even if it is only looking for food or human contact, a kangaroo may still become aggressive). Don't act aggressively towards the kangaroo, as this will simply reinforce the idea that you are a threat.
If you are approached by an aggressive kangaroo you should keep it at a safe distance so that it can't kick or scratch. For example, hold up a stick or branch, or stay behind a fence or a tree. Move away from the animal as quickly as you can. Turning your back on it and running could be dangerous as a large male can easily outrun you and still kick at the same time. Turn side-on and protect the front of your body with your arms and keep your head as far away from the kangaroo as possible to minimize the risk of being scratched on the face.
If it is a large male that has been displaying dominance behavior, it may see you as a threat. Protect yourself and let the kangaroo know you are not a threat by giving a short, deep cough, avoiding eye contact and crouching down as you move away.
Females and smaller male kangaroos are less likely to be aggressive but may approach if they are used to being fed or have had a lot of human contact. Even though females are much smaller than males, they can scratch and kick and could pose a safety risk - particularly to small children.
Avoid the tails of kangaroos as well - while other animals have limp tails that can do no harm, kangaroos can swing their tails so powerfully that they can easily break a limb.
As a last resort, if you can't escape an attacking kangaroo, roll up into a ball on the ground with your arm covering your neck and call for help. Try to roll or crawl away to a safe place.
Of the hundreds of known species of sharks, only a handful are regarded as posing a significant risk to human safety and attacks on humans are rare. The rarity of shark attacks however does not take away from the serious nature of a fatal attack when it does occur. Nor does the seemingly random nature of shark attacks help to allay fears about being bitten. Sharks usually attack because they think you are a seal, a turtle, a fish, or various other types of prey. Sometimes they test bite if they are curious, but sharks do not intentionally bite, attack, or kill humans.
Here are a few common sense tips to reduce the risk of encountering sharks:
- Swim close to shore.
- Swim, dive or surf with other people.
- Avoid areas where there are large schools of fish, dolphins, seals or sea lions and close to birdrookeries.
- Avoid areas where animal, human or fish waste enters the water.
- Avoid deep channels or areas with deep drop-offs nearby.
- Do not remain in the water with bleeding wounds.
- Look carefully before jumping into the water from a boat or jetty.
- If spearing fish, don't carry dead or bleeding fish attached to you and remove all speared fish from the water as quickly as possible.
- If schooling fish or other wildlife start to behave erratically or congregate in large numbers, leave the water.
- If you see a shark, leave the water as quickly and calmly as possible – avoid excessive splashing or noise.
- Main article: Venomous snakes
Few snakes are likely to consider adult humans as prey and a lot of snakes prefer to avoid people. Some venomous species, however, can be deadly.
General advice is to never try to pick up, harm, or kill a snake. If you see a snake, just move on or call in a professional snake catcher to move the animal. A lot of people are bitten when attempting to handle snakes.
It's usually impossible to discern whether a snakebite is venomous by the shape of the bite or the snake, unless you can recognize the specific species. Treat any snakebite as fatally dangerous unless you're certain it's not.
Generally, treatments presented outside the medical field do not work. Instead, you should get proper medical aid and try to avoid deteriorating until the medical aid arrives. To do, the victim of the snake bite needs to rest immediately, completely, and comfortably so the circulation of the venom is slower. The victim needs to be calm, also for this reason. The part of the body damaged by the snake needs to be lower than the rest of the body. If possible, set it using strong branches or the like, so it moves as little as possible. There also exist venom suction pumps which are considered more effective than sucking with the mouth, but studies show that their effects are apparently also negligible. If you have one, use it if you have time, but don't let it delay the victim's evacuation.
Taking a photo of the snake could be very helpful for the doctors. No need to actually catch or kill the snake; it's not like they can or need to produce anti-venom on the spot. They only need to be able to recognize the species to know what anti-venom and other treatments to apply.
Stonefish (genus Synanceia) are a venomous fish; their sting causes excruciating pain and can be fatal. They get their name from their mottled color and tendency to lie on the bottom looking much like a stone; they are quite difficult to see and avoid. In some areas it is common to wear running shoes while swimming to protect against being stung.
An antivenin is available and anyone who is stung should try to get it as quickly as possible. First-aid treatments include hot water, which breaks down the venom, and vinegar, which reduces the pain.
The Pterois genus, most commonly known as lionfish are a venomous fish characterized by conspicuous warning coloration with red, white, creamy, or black bands and venomous spiky fin rays. Stings are extremely painful and can lead to nausea, convulsions, temporary paralysis, heart failure, and, in extreme cases, death. Young children and people with weak immune systems are particularly susceptible.
Treatment is available and should be sought as a soon as possible.
Though native to the Indo-Pacific they have spread throughout the world, and are common in the Caribbean. In Florida and The Bahamas they are treated as invasive species, and any sighting should be reported to wildlife managers.
American elk, moose, deer, bison, goats and cattle can attack people and as big as they are, bison can sprint three times faster than humans can run. They are unpredictable and dangerous and its best to keep a fair distance between you and the animals – if it changes its behavior due to your presence, you are too close. Nevertheless, in North America and Europe a much greater danger from large ungulates is car crashes.
In Africa, buffalo rank with hippos as the most dangerous animals, well ahead of animals perceived to be more deadly in the West such as lions and rhinos.
Boars are widespread in Europe and most of Asia. They are mainly a risk for animal collisions and food scavenging. In rare cases they are aggressive, especially if they are provoked by dogs.
In some locations, feral pigs become a nuisance similar to natural boars.
Wild boar attacks on humans are not common but do occur occasionally. Usually, boars, like most wild animals, will avoid interactions with humans. Due to the clearing of natural boar habitats, the number of interactions, including aggressive ones, between humans and boars has increased. Boars eat everything, so they might look for food in farmlands, campsites, landfills, and gardens.
When dealing aggressively with a human, boars will charge at them. These are sometimes bluff charges, but in other cases violent contact will be made. While the impact of the large, hard-skulled head may cause considerable damage itself, most damage is inflicted by the boar's tusk. When ramming into a person, the boar will slash the tusks upwards, creating sizable open lacerations on the skin. Due to the height of the boar relative to a human, most wounds are inflicted to the upper legs. Some attacks are provoked, such as when hunters wound a boar, which then counterattacks. Male boars become most aggressive during the mating season and may charge at humans at such times. Occasionally, female boars will attack if they feel their piglets are threatened, especially if a human physically comes between them and their young. Although a majority of boar attack victims recover with medical treatment, fatalities do occasionally occur.
More than a billion domestic cattle graze the Earth, outnumbering all other animals of similar size. They are dangerous in herds.
The male of the species is particularly aggressive. Even under controlled conditions, an event like the Running of the Bulls in Pamplona can and has resulted in injuries or fatalities.
Cattle, including bulls, roam freely throughout much of India. While most of them are harmless and are used to being surrounded by humans, the bulls can charge at you at any moment for no apparent reason.
The term "elk" has different meanings in different varieties of English. Outside North America, it refers to the animal we describe as a moose below. In North America, it means the quite different animal shown in the photo. An alternate term is wapiti, borrowed from a Native American language.
In September and October herds of North American elk gather for their mating season, or “rut.” During the rut, the male “bull” elk are irritable, aggressive and extremely dangerous to onlookers who get too close.
The elk calving season takes place in April and May of each year. During this time, female elk, or cows, become irritable and highly protective of their young calves. Though they may look harmless, cows are extremely dangerous during calving season.
Elk are wild animals which must be observed from a safe distance to avoid injury or death. If an animal is carefully watching you and appears “jumpy” when you move, you are too close.
Moose aren't inherently aggressive, but will defend themselves if they perceive a threat. When people don't see moose as potentially dangerous, they may approach too closely and put themselves at risk. More people each year are injured by moose than by bears.
Enjoy viewing them from a distance. Cow moose are extremely defensive of their young so use extra caution around cows with calves and never get between a cow and a calf.
In the summer months, moose blend in well to their environment and can be surprisingly hard to see for such large animals. They are likely to stand their ground even when they hear people approaching, so pay close attention to your surroundings, especially in prime moose habitat such as willow thickets or around streams or ponds.
If you do find yourself close to a moose
- If it hasn't detected you yet, keep it that way.
- If it knows you're there, talk to it softly and move away slowly.
- Don't be aggressive – you want to convince the moose that you aren't a threat.
- If you think the moose is going to charge you, take cover or run away. Unlike with bears, it is okay to run from a moose.
- Moose cannot climb trees, so getting up one is reasonably safe. Try to choose a fairly large tree and get high enough that the antlers cannot reach you.
Watch for signs that the moose is upset. If its ears are laid back and hackles are up it is likely to charge. Most of the time, when a moose charges it is a 'bluff', or warning for you to get back – a warning you should take very seriously! Once a moose bluff charges it is already agitated. If possible, get behind something solid (like a tree or a car).
They usually won't chase you and if they do, it's unlikely that they'll chase you very far. If a moose knocks you down, curl up in a ball and protect your head with your arms and keep still. Fighting back will only convince the moose that you may still be a threat. Only move once the moose has backed off to a safe distance or it may renew its attack.
The musk ox lives in the Arctic and in some nature reserves in Norway and Sweden. While they avoid humans, if threatened the herd will not run away and instead forms a defensive formation, and may attack if humans come closer. Keep a safe distance of at least 200 meters.
Wolves rarely hunt humans, but they may come after livestock, food supplies or trash. Animals gradually lose their natural avoidance to people when they are protected from harm by people, or where humans act passively towards them. This is called habituation. Habituated wolves become comfortable around people and may venture quite close to people. It is very important to understand that these habituated wolves are actually the ones most likely to suddenly act aggressively.
Wolves also quickly learn that food is often found in human garbage. When wolves seek out human foods they have become food-conditioned. If a wolf is fed by people it begins to expect handouts. If that wolf approaches a person but gets no food, it can become suddenly aggressive. This type of aggression is probably responsible for many of the bites that wolves have inflicted on people.
Wolves have generally not learnt to hunt people for food, and thus any pack and especially any individual wolf will hesitate doing an attack against a person not showing weakness. If a wolf comes near, do neither run nor try to get friendly, but back off without turning your back. If the wolf follows, striking with a walking stick in its direction or similar aggressive behaviour can help keep your psychological advantage, but is usually unnecessary. In most countries with wolves, aggressive behaviour against people is very rare indeed.
Rabid wolves, on the other hand, often attack without being provoked. They do not attack to kill but the bite requires urgent treatment, as rabies is lethal.
Wolves regard dogs as rivals, and show them no mercy. Many hunting dogs have been killed by wolves and some large dogs will attack and kill wolves. Various wolfhound or guard dog types are bred for this, and some dogs will even make suicidal attacks against a pack. See also travelling with pets.
Foxes are too small to be of any significant threat to humans, though they often scavenge through human trash, and may attack small livestock like chickens, as well as some smaller pets. Foxes that attack humans unprovoked are usually infected with rabies, so if you are attacked by one, it is imperative that you seek medical attention as soon as possible.