Dolphins sometimes have fun by blowing bubbles and creating rings of air underwater, which they then swim through.
17
Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
12
The difference between antlers and horns is that antlers are shed each year and are made of bone while horns are kept for life and are made of living tissue and bone with a sheath that is very similar to human finger nails.
10
Early American humans hunted car-size armadillos and used their shells for houses.
12
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
Cows as they are today never existed in the wild and were domesticated from aurochs some 10,500 years ago.
6
The largest breed of rabbit is the Flemish Giant.
65