Koalas are often unfairly labelled as “stupid,” but that’s not entirely true. While they have small brains and simple behaviours, they’re perfectly adapted to their eucalyptus-filled environment. Their slow movements help conserve energy, and their strong memory helps them navigate trees. So, while they’re not problem-solvers like some animals, they’re smart in their own way.
The Koala Brain: Smaller Than You’d Think
Koalas have one of the smallest brains in proportion to their body size of any mammal. In fact, their brain only fills about 60% of their skull, and the rest is fluid! This has led some people to call them “stupid” — but that’s not entirely fair. Their brain may be small, but it’s perfectly suited to their slow, sleepy lifestyle, spending up to 20 hours a day snoozing in trees. Why use brainpower when your diet and routine never really change?
There are lots of things that make koalas stand out from the rest of the animal kingdom. For example, they have poor eyesight but make up for this with excellent senses of smell and hearing. These allow them to be excellent at detecting both predators and ripe/ideal food sources. At the same time, their most unique feature is their sub-par intelligence.
But WHY are koalas stupid? Let’s discuss.
Why do koalas have the reputation of being stupid?
Let’s begin with some biology. Koalas have one of the lowest brain to body mass ratios of any mammal. Their brains are also almost entirely smooth, meaning their cognitive abilities are few and far between.
Eucalyptus: Not Exactly Brain Food
Koalas eat almost nothing but eucalyptus leaves, which are tough, toxic, and low in nutrients. This diet provides very little energy, so koalas need to conserve as much as possible — hence the slow moves and long naps. Because eucalyptus is so specialised and difficult to digest, koalas have evolved an amazing gut rather than a sharp brain. So, in a way, they’ve traded brainpower for digestive superpowers!
Similarly, they have no concept of what rain is. Most animals, when getting drenched in rain, would run for shelter to protect themselves. Not the humble koala, which simply sits in the rain wondering why it’s getting wet.
Almost laughably, the mere fact that they eat eucalyptus leaves is stupid. A koala’s diet consists primarily of these leaves, and yet they have little to no nutritional value. They also contain little to no calories and are quite literally poisonous. You heard that right. Koalas have had to adapt specifically to be able to consume them and yet haven’t adapted to eat anything more substantial or beneficial.
In fact, expending little to no energy is part of their survival tactics. By having small, smooth brains they don’t use much energy with silly, pointless things like thought or spatial awareness and can instead conserve the extremely small amount of energy they gain from their diet of nutrients-devout poison.
Can Koalas Learn?
Despite their reputation, koalas can learn to recognise their home ranges, return to favourite trees, and even navigate through complex environments — especially after habitat destruction. They may not be great at solving puzzles or opening jars like some other animals, but they do show signs of memory and basic problem-solving when it matters most: survival.
For more answers to “are koalas stupid” read this blog from the University of Melbourne.
Other animals with the reputation for being ‘stupid’
🦃 Turkeys
Turkeys are often mocked for supposedly drowning in the rain by looking up with their mouths open (a myth!). In reality, they’re quite social and can even recognise each other’s voices — not so silly after all.
🐟 Goldfish
You’ve probably heard the claim that goldfish have a three-second memory — but studies show they can remember things for months, and even be trained to do tricks!
🐓 Chickens
Often seen as simple farm birds, chickens can actually recognise over 100 faces, use basic logic, and even dream. Their bad reputation is more about our underestimation than their brainpower.
🐑 Sheep
Sheep get flak for “following the crowd,” but they’re not mindless. They have excellent memories, can navigate mazes, and form strong emotional bonds with other sheep and even humans.
🐛 Sloths
Their slow movement and “blank” expressions have given sloths a reputation for being dim, but they’re just super energy efficient. In their rainforest homes, slow is smart — and helps them avoid predators!
🐊 Ostriches
People once believed ostriches buried their heads in the sand when scared. Not true! They’re just lowering their heads to blend in. These giant birds actually have strong survival instincts and can run up to 45 mph.
Lemmings must be mentioned, considering their infamous status as stupid. Lemmings, which stand at a mighty 6 inches long, often fight cats, birds of prey etc. when the need arises. They fight using their large front teeth, something the predator will have definitely noticed prior to the fight thanks to the lemming’s large, distinctive cheeks. A true marvel of evolution is the lemming.
Extra information
Animal-Club provides animal parties or animal handling workshops. You will be able to see, learn and interact with many wonderful animals with the help of our presenters. Our mobile zoo has many friendly animals such as rabbits, tarantulas, geckos, vinegaroons and more, perfect for an animal party. We can also come over to your school for an animal school visit or arrange for an animal workshop with us where the children can learn about looking after animals and animal behaviour, and have fun too.