There wasn't a single pony in the Pony Express, just horses!
57
Bats sleep 18-20 hours per day.
5
It has been calculated that a single breath from a mature blue whale can inflate up to 2,000 balloons.
492
What you find when you shave the striped fur off of a tiger? Striped skin.
163
Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
12
Roosters can't crow if they can't fully extend their necks.
28
Squirrels forget where they hide about half of their nuts.
698