Social Science

Compost worm squirm

Wiggle away my pretties

March 16, 2011

Epigealworms by RoseEveleth

My grandparents live in a colonial house in Connecticut, and they have a lot of worms in their soil. I know because as a kid, whenever we went there for Thanksgiving, I would take a foil baking dish out of their kitchen, fill it with dirt, and dig up as many worms as I could to put into my “worm zoo.”

The worms that I would plonk into the dish would bury themselves as quickly as they could. It sounded a lot like this. They were probably Eisenia fetida, or Red Worms, one of the more common worms used in home composting systems. Worm-assisted compost is also called vermiculture, and worms make some of the best compost around.

When a worm eats, it wiggles through the soil, garbage, or whatever else it’s in. As it moves, it takes in both the plant bits and some dirt along the way. The dirt helps to cut the plant bits into super tiny pieces, and the worm absorbs the nutrients and poops out the leftovers. Good thing for gardeners those leftovers are still full of plant nutrients, minerals and all kinds of stuff that helps plants grow.

They also make something super delicious: worm tea. That’s the liquid form of worm “casts” which is really just a polite word for worm poop. The tea is rich in nitrogen, phosphate, calcium, magnesium and potash, and is used as both plant fertilizer and as a natural pesticide.

Unlike most species of worms, Red Worms are “epigeal,” which is just a fancy term for surface dwelling. They live, burrow, chomp and poop in the top few inches of the soil.

These worms are fleeing from the sunlight, after the lid was rudely lifted off their compost box. They don’t have eyes (the better to flee from you with!) but they do have light sensing cells in their skin. Those cells tell them when they’ve reached the surface, which means they should turn their worm butts around and burrow back down.

Earthworms aren’t only for your casual composter. In India, a recent study evaluated their use in mitigating the millions of tons of waste that the sugar industry produces. (The same team looked at using waste sludge from paint and pigment factories as worm food.)

Darwin actually described the action of worms and published a book in 1881 called The Formation of Vegetable Mould Through the Action of Worms, With Observations on Their Habits. He dug a trench across a field behind his house, and placed stones along it. He then waited for 20-30 years and watched where the stones went (talk about commitment). They sank, due to worms turning the soil over. He also played the worms the bassoon, to see if they could hear. During his lifetime, the book actually sold better than On the Origin of Species.

If you’re interested in building a compost bin with worms, here’s a handy comic to guide you.

Bonus Fact: My dad tells me that they used to go out at night to hunt the big worms that came out to mate (he calls them “nightcrawlers”). They would cover their flashlights with a cloth, and walk slowly and softly – because the worms could feel the vibration of their footsteps – and then snatch the worms up with a snap of the wrist. (He demonstrated this to me recently, in our kitchen, crouching and tiptoeing across the tile floor).

Sound recorded by Beboncan at the Free Sound Project.

About the Author

Rose Eveleth

Rose Eveleth graduated from the University of California, San Diego with a B.S. in ecology and a minor in writing. She spent the last four years there poking around in labs, studying krill, climbing trees, riding bikes and perfecting her fish doodles. A sucker for being lost in strange places, she recently wandered her way through Costa Rica, Portugal, Tokyo and Bonaire and is excited to take her wandering to the epicenter of strange places, New York City.


1 Comment

Cheryl Warren says:

Enjoyed your excellent article! I’ve been wondering a lot recently about the science of worms while planting my spring garden. I appreciate your personal history and had no idea that Darwin wrote such a book after years of observations. Thank you!

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