A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Gorillas can catch human colds and other illnesses.
205
There are approximately three chickens for every human on Earth.
13
Rattlesnake mating sessions have been known to last more than 22 hours.
232
Cats recognise the voice of their owner, but never evolved to care.
22
The colossal squid has the largest eyes in the world.
4
Alligators can live up to 100 years.
337