Only a worm
By By Robert A. Hedeen, Naturalist
Only a worm is a common expression that clearly indicates where worms belong in popular opinion, and to call someone a worm is to degrade him. Any small creature that crawls, is long and slender, and is without visible legs is usually classified as a worm. In this broad sense, however, the name may be applied to animals that are not truly worms in the zoological sense: snakes, some lizards, many mollusks, larvae of insects, and to several other entire groups of animals.
Mankind accepts without much thought, and certainly without thanks, the many benefits we derive from what we call lower animals, and in the eyes of many, nothing is lower than an earthworm. The truth of the matter is we profit greatly from sharing the planet earth with earthworms that greatly enhance our agricultural practices.
Earthworms are continuously honeycombing the soil beneath our feet, rendering it light and porous and insuring better penetration of light and moisture. And, like plowmen, they constantly work over the surface of the soil, making it infinitely more fertile.
In addition to formulating the theory of the evolution of species by means of natural selection, Charles Darwin was an expert on the biology of earthworms, as well as in other areas of the natural sciences. Darwin determined that one acre of fertile ground in his native England harbored up to 50,000 earthworms. The naturalist was also able to calculate that these 50,000 worms carried more than 18 tons of finely-ground soil to the surface in a single year. At that rate, in 20 years, a layer three inches thick would be transferred from the subsoil to the surface of an acre.
As they move about underground, earthworms can force their way through soft dirt, but must literally eat their way through hard and compacted soil. The soil is pulverized as it passes through a muscular, grinding gizzard and is deposited on the surface as castings. Decaying organic matter and microorganisms provide food for the underground worms, as well as leaves and other vegetation on the surface, which they may drag into their catacombs when they occasionally venture topside during the night. About the only defense mechanism an earthworm has is a set of bristles on each segment of its body. These setae can be set to prevent the worm from being dragged from its burrow by a predator.
In addition to improving the quality and quantity of the soil, the rearing of earthworms is big business. In a recent edition of an outdoor magazine, I noticed several advertisements offering earthworms for sale. These ads stemmed from 13 states: from New Jersey, to Georgia, to Illinois, and west to California. In some cases, a supply of worms was offered along with detailed instructions on how to propagate them and how you can go into business for yourself. One worm rancher boasted in his ad of a shipping capacity of 500,000 worms daily. If he sells only a small fraction of this stated daily capacity, he is well on his way to becoming a millionaire.
The vast majority of the earthworms raised on these worm farms or ranches, as they are called, are sold as fish bait, but the creatures may be in demand at other times for various reasons. Some years ago after a series of devastating floods in the Netherlands, several million earthworms were sent to that country from sources in the United States. The agricultural endeavors of the worms were credited with contributing greatly to the speedy return to cultivation of the inundated Dutch farmlands.
And these denizens of the underworld are of considerable value in other ways, Biologists consider them to be typical of the great invertebrate (without backbones) animal kingdom, and they are frequently used in research of all types. Almost every beginning biology class studies the anatomy and physiology of both living and preserved earthworms.
The soft, nutritious body of the earthworm furnishes a valuable source of food for other animals, especially birds. In some cultures, humans enjoy earthworms as food. In parts of Australia and New Zealand one species attains a length of 11 feet and has a diameter close to an inch. The natives relish this animated garden hose as a gourmet item on their menu. .
Most fishermen use a shovel or spading fork to dig in the ground to obtain enough bait worms for an afternoons fishing on the lake or river. If the worms are scarce, however, this can involve quite a bit of effort. But my daughter-in-laws uncle, Wayne Pence, of Wyoming, Iowa, has devised a quicker and less strenuous way to secure an adequate supply of bait. He sinks a metal rod, to which is attached a wire with a plug, a few inches into the ground. After connecting to an electrical outlet, a current is shot into the ground, driving the worms to the surface, stunning them but not electrocuting them. I watched Pence perform this operation on one occasion and was amazed at the number of bait worms he was able to collect in a very short time and with very little effort. Too bad Darwin did not have available the Pence worm-shocking apparatus, or he would not have had to expend so much time and energy digging up an acre of England in order to count the worms residing there.
Dr. Robert Hedeen is a former resident of eastern Maryland, with degrees in zoology and botany. He is a former professor of biological science. He has had 30 scientific papers published, has written numerous magazine articles, and is the author of two books on marine biology of Maryland.