Cats recognise the voice of their owner, but never evolved to care.
22
In Australia, there are spiders big enough to eat snakes.
20
Some older/less efficient worker termites will develop 'backpacks' of toxic chemicals that explode when the termite is threatened. They are essentially used as suicide bombers when the colony is being attacked.
8
During World War 1, starving wolves amassed in such great numbers that Germans and Russians had a temporary cease fire to fight off the wolf attacks.
45
Some lizards, in which the tail is a major storage organ for accumulating reserves, will return to a dropped tail after the threat has passed, and will eat it to recover part of the sacrificed supplies.
13
Jumping fleas can accelerate 50 times faster than the space shuttle.
218
Leonardo Da Vinci loved animals so much that he used to buy caged animals at the market just to set them free.
57