Only 3% of bird species have penises.
0
Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
12
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
When a drone bee mates with a queen, its ejaculation is so powerful that it can even be heard by the human ear.
5