The lifespan of mammals is about 1 and a half billion heartbeats.
127
The average housefly weighs 10 to 15 millionths of a pound.
33
A duck's quack doesn't echo, and no one knows why.
173
All species of beetles are edible.
21
How does a shark find fish? It can hear their hearts beating.
31
Spiders have transparent blood.
56
Baby whales grow at an average rate of 10lbs per hour!
37
Frogs sometimes eat enough fireflies that they themselves glow.
71