A Worm’s Eye View

Whenever you embark on an archeological dig in your back yard in a search for notable fossils, on the way down there will be earthworms. They may not spark excitement but know that lowly worms carry a certain reputation and rank and have for quite a time. Perhaps it started with Aristotle who called worms the “intestines of the earth.” They earn that title.

However, it wasn’t until around 1492 that worms, along with many other Europeans, discovered America when they sailed in aboard ships that eventually landed on our shores. Earthworms immediately made themselves at home and set to the task of reshaping the structure of American soil. This had consequences. As they devoured the existing leaf litter of the time, the food that countless insects fed on, the insects were starved off. The birds and mammals on up the food chain who were dependent on the disappeared insects were also out of edibles. Creatures that had thrived died. Others saw environmental openings and took their place.

Today the estimate is that some 1.75 million worms inhabit each acre of fertile arable land. It is those working worms that make land arable, prepped to grow crops. They are smooth-skinned with a front end that houses a tiny brain and mouth and a back end and are able detect light and vibrations without the aids of eyes or noses. Though they lack a skeleton their efficient muscles move them along in lengths varying from  .039 of an inch to 78 inches long. And move along they do loosening, mixing and oxygenating the soil as they burrow channels and wiggle about their business of eating breaking down organic matter such as leaves and grass. They follow up by contributing their castings—worms’ particular remains of their day—a very valuable form of fertilizer sometimes called worm poop. Their casts can add 5 times more nitrogen, 7 times more phosphorus, and 1000 times more beneficial bacteria to the original soil and their wriggling and burrowing also spreads these micro-organisms around. If turn about is fair play, worms are themselves now a food source for other species including hedgehogs, frogs and birds.