Cats recognise the voice of their owner, but never evolved to care.
22
The first known contraceptive was crocodile dung, used by Egyptians in 2000 B.C.
79
Cymothoa exigua is a type of parasite that enters through fish's gills, eats their tongue, and then replaces it.
6
Denmark has twice as many pigs as there are people.
66
Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
12
Travis was a chimpanzee who socialized with humans since birth. He could log onto a computer to look at pictures, watch TV using a remote control, brush his teeth, feed hay to his owner's horses, water plants, and learned the schedule of passing ice cream trucks.
11