Re: Do earthworms have brains? How do earthworms survive in the dirt?

Hi,

Sorry I couldn't answer your question in 4 seconds but these things take time!

Earthworms are the simplest organisms to have a central nervous system, which includes a distinct brain that is connected to groups of nerve cells organized as a cord running along the entire length of the body (see picture). This arrangement, with a brain at the front connected to a nerve cord behind is the basic design for all organisms with central nervous systems, from the earthworm on the hook to the human on the other end of the fishing rod. But although we can discern a separate brain in worms, it is not the case that the brain is in sole charge of the animal. Indeed, even with its brain removed, worms are able to perform many types of behavior, including moving around, burrowing, feeding and even learning their way around a maze.

To find out more about the brains of lots of different animals take a look at the Invertebrate Nervous System website.

To answer your second question, earthworms survive very well in the dirt. In order to move forward underground an earthworm must first eat the dirt which is in front of it so that it can move into the space where the dirt was. This dirt then passes through the worm's body and out the other end. On its way through, the worm extracts water and particles of food from the dirt. This arrangement suits the worm well since it is effectively living inside it dinner.

For more information on worms you may want to check out the following websites...

Annelida
Annelid Resources
Earthworm Information
Phylogeny of Annelida and allies
Worm Digest
Worm Web Ring

I hope this helps.

Good luck!

Rob Cruickshank