One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
The reindeer is the only mammal that can see UV light.
17
The largest earthworm on record was found in South Africa and measured 22 feet.
151
In 2011, a male tiger in India adopted a litter of orphaned cubs, taking on the role of ‘mother’. Wildlife officials say such behavior had never been observed before.
9
Sheep, goats, octopuses, and toads have rectangular pupils.
7
Cows as they are today never existed in the wild and were domesticated from aurochs some 10,500 years ago.
6