A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
When cats are happy, they may squeeze their eyes shut.
10
When dragonflies mate, their tails form a love heart.
22
Sharks have been on the planet longer than trees.
14
In 1955, the citizens of São Paulo were so upset with their government that they elected a rhinoceros named Cacareco (meaning rubbish) to the city council in protest, with over 100,000 votes.
18
Lobsters have blue blood.
476