Sheep, goats, octopuses, and toads have rectangular pupils.
7
Cats recognise the voice of their owner, but never evolved to care.
22
Jumping fleas can accelerate 50 times faster than the space shuttle.
218
When Washoe, the first chimp to use sign language, was told that her caretaker's baby had died, she signed "CRY."
20
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
Leonardo Da Vinci loved animals so much that he used to buy caged animals at the market just to set them free.
57
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23