Forest Preserve District of Cook County, Illinois
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Hair Snakes
Nature Bulletin No. 101   February 1, 1947
Forest Preserve District of Cook County
William N. Erickson, President
Roberts Mann, Supt. of Conservation

Farm boys have more fun than city boys. Every farm boy has watched the "hair snakes" sometimes found wriggling in drinking troughs for horses and cattle, or in puddles on a country road. They and their fathers will argue obstinately that these are hairs, from a horse's mane or tail, that turned into snakes. Phooie.

Hair snakes are not snakes at all. They are roundworms. There are four common groups of worms here: annelids, which include earthworms and sewage-sludge worms; tapeworms; flatworms; and roundworms. The last three are called the "Lower Worms" and many of them are parasitic in other animals.

The adult hair snakes, called "Gordian worms" by biologists because frequently found in tangled masses suggesting the Gordian knot of mythology, do resemble animated horsehairs or fine wires. They are covered with a thick tough skin and teel like the wet gut leader on a fishing line. They have a pair of eyes and many fine bristles along the body which are sensitive to touch. Having no mouth, they cannot eat although they may live for weeks or even months. They are freeliving -- only in the young stages are they parasitic.

The female lays a white thread-like string of eggs, sometimes several feet long and containing millions of tiny eggs, often found along the shores of streams and lakes, or on aquatic plants. After hatching, the tiny young bores its way into some aquatic insect such as the mayfly larva where it passes through one stage of its development. It may remain there until the insect is eaten by a beetle or a fish. Or, if the insect dies, it may find its way into the body of a grasshopper, a cricket, or a beetle, where it completes the second larval stage and becomes an adult worm.

If this second insect "host" falls into a brook or pond, the worm breaks through the body wall of the insect and seeks a mate. Otherwise it breaks through, falls on land, and may be swept into a body of water, or a puddle, by rain. Once we saw two boys, both sons of zoologists, having a swell time dropping grasshoppers into a tub of water and betting on whether a hair snake would emerge, thus completing the cycle.

The roundworm goes round and round.

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