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
Sharks, like other fish, have their reproductive organs in their chests.
248
An alligator can go through 2,000 to 3,000 teeth in a lifetime.
268
Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
12
The Basenji dog is the only dog that is not able to bark.
4