Some think worms are awful; they’re parasites, in gravesites and science fiction movies. Earthworms (of the scientific order Megadrilacea), however, get something of a pass. Maybe it’s because they are beneficial and are associated with productive gardening. They are harmless to us humans and simply toil away out of sight underground and are a sign of a healthy ecosystem. Maybe it’s because we subjugated them so mercilessly during our childhood fishing expeditions and we’re feeling guilty.
It was not always this way because, believe it or not, most earthworms are not from here but came from England (and other parts of Europe). It seems that North America’s original earthworm population was largely wiped out by Ice Age freezes. Our nation’s forefathers must have either been extremely environmentally conscious and forward thinking to purposely re-introduce the animal to U.S. soil or they just had the dumb luck to cross the Atlantic with the worms hidden in their potted plants and ship’s ballast. There are 1,600 species worldwide and Ailoscolecidae is one of the most popular in Louisiana, commercially raised for fishermen or turned loose in gardens. Anyway, once they were here it was recognized the great benefit of having one’s soil pass repeatedly through their digestive systems.
So why do they swallow dirt? Besides trying to glean nutrients from decaying roots and leaves, the occasional nematode, protozoan, rotifer, bacteria or fungi are considered a treat (especially when they wiggle). Animal manures and other animal remains are considered delicacies.
Earthworms don’t have eyes and, therefore, don’t know if it is dark outside or light but they do love it wet. If it gets too dry they try to burrow more deeply, up to six feet. After a rain, in dew or heavy humidity they find it comfortable to slither around on the surface but they do so at their peril. There is always the possibility that a hungry red, red Robin will come around bob, bob, bob’n along...
Also, earthworms are not known for their powers of reasoning and sometimes miscalculate to blunder onto a sidewalk. If they get caught on one on these concrete deserts in the sun they can meet their end by shriveling up and dying on the spot and are of no use to anyone.