Because beavers’ teeth never stop growing, they must constantly gnaw on objects to keep them at a manageable length. Their teeth would eventually grow into their brain if they didn’t maintain them.
Beware an ant uprising! There are one million ants for every human in the world. These resilient creatures also never sleep and do not have lungs.
Oysters can change gender depending on which is best for mating. Talk about successful adaptation.
Butterflies have two compound eyes consisting of thousands of lenses, yet they can only see the colors red, green and yellow.