When a male gentoo penguin "falls in love" with a female penguin, he searches the entire beach to find the perfect pebble to present to her.
25
Parrotfish make themselves a kind of mucus 'sleeping bag' which masks their smell from predators and keeps parasites away.
4
Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
12
Sloths take two weeks to digest their food.
243
The oldest recorded elephant lived for 82 years.
213
A cat rubs against people not only to be affectionate but also to mark out its territory with scent glands around its face. The tail area and paws also carry the cat's scent.
293
The first known contraceptive was crocodile dung, used by Egyptians in 2000 B.C.
79