Cats recognise the voice of their owner, but never evolved to care.
22
Squirrels forget where they hide about half of their nuts.
698
Sergeant Stubby was the only war dog to be promoted to sergeant through combat in WWI. He saved his regiment from surprise mustard gas attacks, found and comforted the wounded, and even once caught a German spy by the seat of his pants, holding him there until American Soldiers found him.
16
A dog's naked behind leaves absolutely no bacteria when pressed against carpet.
250
Sharks have been on the planet longer than trees.
14