The earthworm is one of the slimmest creatures in this world.
There are approximately 2, 700 different species of earthworms.
Charles Darwin spent 39 years studying earthworms more than 100 years ago.
Worms are hermaphrodites. Each worm has both male and female organs.
Earthworms usually crawl out of the mud after heavy rains, as the soil becomes too damp for them to survive.
The giant South African earthworm (Microhaetus rappi) can grow up to 6.7 meters. The largest worms reach 2.5 centimeters in diameter.
The Australian species, the large earthworm (Megascolides australis), can grow up to 3.7 meters in length and is known for its gurgling noises when buried in the ground.
There can be over a million earthworms in one acre of good soil. Many of the species of earthworms now found in North America were originally introduced by European settlers.