Very few of us continue to read biology books after we finish school, which is why documentaries are a great alternative. And even though they describe nature in a fascinating fashion, we’re offering you the chance to learn some facts about the world you’ve probably never heard before.

We at Bright Side never get tired of finding out new things that change our perception of the world.

Female 3-fingered sloths become 200% more active during mating season. They make sounds like bird calls or shrill whistles to attract males.

Armadillos cross streams or rivers, walking on the bottom. They can hold their breath for up to 6 minutes. By swallowing air, the animal can also regulate its buoyancy.

Snakes sleep with open eyes. They don’t have eyelids — instead, they have transparent scales. You can notice them during molting when the eyes become cloudy.

The Arctic woolly bear moth may remain a caterpillar for up to 7 years. In this dormant state, it can survive temperatures as low as −94°F.

The venom of the inland taipan is the most toxic among all other snakes. It’s 50 times more powerful than that of the Indian cobra.

So don’t eat bananas or anything banana-flavored when you are near bees, or you might get stung.

Giant armadillos have the biggest number of teeth among mammals — from 80 to 100. They don’t have enamel and grow throughout their entire life.

Rabbits are the only mammals that don’t have paw pads but a thick layer of fur instead.

Pacu fish have human-like teeth. They are mainly used to crush nuts and fruits.

© Erik Klietsch / Shutterstock

What amazing animal facts do you know?