Sheep, goats, octopuses, and toads have rectangular pupils.
7
Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
12
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
Dogs sometimes fake being sick to get attention.
26
When you shave a guinea pig it looks like a little hippo.
19
The cat brain weighs about 30g.
167
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212