Are Koala Bears Dangerous?

The koala bear is known to sleep all day, but they can fiercely defend themselves with sharp teeth and claws. Let’s look at whether koalas are dangerous to people.

Nov 16, 2023By Lisa Szymanski
are koala bears dangerous

Koalas are known as Australia’s cute and cuddly creatures, but there’s another side to them that you may not be aware of. These solitary animals spend their time in trees feasting on eucalyptus, but if they feel threatened, they won’t hesitate to fight tooth and claw. Koalas are usually docile, but they do pose a few threats to people when they feel threatened. It may be hard to believe that a koala bear could be a threat, so let’s determine why koalas are dangerous.

Koalas Can Make People Sick

koala bear sitting on a tree branch

Up to fifty percent of koalas in the wild are infected with a disease called Chlamydia. This illness is an STI found in humans, but a different strain affects these Australian marsupials. Chlamydia causes uncomfortable symptoms ranging from blindness to near-fatal complications of the urinary tract and cannot be cured. What is shocking is the fact that a koala can pass Chlamydia to a human. It is transmitted to people who are exposed to the urine and feces of these animals. If you come across a koala bear in the wild, it’s best to avoid getting too close to them to protect yourself from exposure.

A Koala Bear is Extremely Fast

a koala bear walking on rocks
A koala is a fast runner.

Koalas are seen as sluggish and sleepy animals that spend 22 hours a day resting and indulging in eucalyptus leaves. Some other animals that enjoy eucalyptus include possums, wombats, smallbirds, and beetles. People have been caught off-guard by the tremendous speed these gray marsupials can reach when they decide to give chase. It takes a lot for a koala to leave their tree and run after you, but it's not unheard of. Koalas can run just over 20 mph, and they become pretty determined athletes when they spot a target. Fortunately, koalas prefer the safety of treetops rather than expend their energy by running around.

Koalas Have Sharp Teeth and Claws

koala in tree with open mouth showing teeth
Koala bears have long teeth and claws.

Koala bears look sweet and peaceful when they’re fast asleep, but they can inflict serious damage on people. The tree-loving koala has long claws that they use to grip trees and branches as they look for food. Their front teeth look like two fangs that act as scissors to pluck a leaf off a branch. Their teeth and claws are perfectly adapted for tree climbing and leaf-eating, but they are sharp enough to cut through human skin. Koalas will also use their claws against predators such as pythons and owls. Although koala bear attacks are infrequent, when they decide to bite and scratch, they will cause painful wounds.

Koalas Can Be Aggressive

close up of koala bear face
Koalas are not well-known for aggressive behavior.

If a koala bear decides to attack you, they won’t give up. These feisty creatures are only around 3 feet tall, but they are tenacious, and if you cross their boundary, they will become aggressive. Koalas establish their territories by marking parts of trees. They will claim space and fight to maintain their homes when threatened. These little bears are defensive of their young, so steer clear of a koala and her baby. Most attacks by koalas are due to people invading their territory or in defense of their joeys. Sick koalas should never be handled, as they will scratch and bite to protect themselves. If you ever come across a koala that is ill or injured, it is best to contact the local wildlife authorities for help.

Can a Koala Bear Kill You?

koala with long claws sleeping in eucalyptus tree
Koalas are generally docile but can attack if threatened.

Koalas have sharp claws and will bite or latch on to you when they attack, but they have not killed a human. This doesn’t mean that they can’t inflict damage. Much like the talons of an eagle, their claws can easily tear through flesh, and scratches can become infected. There is a misconception that koalas are poisonous because they consume a diet high in cyanide. While the leaves that they eat have high amounts of chemicals, these substances are digested and passed through the body. These fuzzy animals do not have poisonous claws or bites, and while they will cause severe injuries, they aren’t known to cause human fatalities.

What are the Dangers of Koalas?

adult koala bear climbing up a tree branch
Koala bears should be respected in the wild.

Unlike large and aggressive bears that people and animals encounter in forests, koalas stay in trees. They will attack if you taunt them or invade their territories. Koalas are not poisonous, and they do not have the bite force of a regular bear to crush bones. This doesn’t mean that you should try to interact with koalas. These adorable animals seem peaceful, but they will scratch and bite if they are picked up or cornered. Another danger of getting too close to a koala is contracting a chlamydia infection if they urinate on you. Koalas carry this disease, and despite the best efforts of conservationists, there is no cure. A koala bear is known the world over as gentle and cuddly but should be left alone in the wild to avoid dangerous encounters.

Lisa Szymanski
By Lisa Szymanski

Lisa is a wildlife enthusiast who enjoys hiking and gardening and has four years of experience volunteering at pet shelters. She is the proud mom of two dogs, a Pitbull named Ragnar, a Boerboel named Blueberry, and four feisty chickens, or as she calls them, the "queens of the yard," Goldie, Gray, Peaches, and Brownie.