Beverly Wiggins, age 10, of Fredericton, New Brunswick, Candada, for her question:

Does a bloodsucker hang on by its teeth?

This wretched creature does have teeth, three sharp teeth that he uses as tiny saws. His aim in life is to pierce the soft skin of some animal or person and suck out the blood. The teeth just dig the hole. The bloodsucker has a mouth somewhat like a suction cup. As a rule, he depends on this sucker to hang on and also to suck out the blood.

This low down member of the animal kingdom is one of those wretched parasites who re¬fuses to make his own living. He feeds on the blood of other live animals, and he happens to be very fond of human blood. Beware of the bloodsucker in marshlands and swampy fields, or when you are tempted to swim in a muddy pond or creek. His wormy body may lie in wait, perhaps stuck to a submerged stone or log. When he senses your living flesh, he swims out and attacks. He uses his three sharp little teeth with the delicate skill of a surgeon, and you may not even feel him pierce your skin.

When you spot him, there is a right and a wrong way to be rid of him. Do not wrench him away by sheer force    his tiny teeth may be left behind in your flesh. It is better to coax him to leave of his own accord. A dab of strong chemical may be painful enough to discourage him, but it should not be strong enough to sear your own skin. A lit match held to his body makes him quit in a hurry, but unless the job is done with skill, you may make matters worse by burning yourself.

The bloodsucker's nasty little teeth are needed to pierce the hole in your skin and are used again when the wretched creature feels himself being pulled away from his dinner. But as a rule, he uses his two round suction cups, one at each end of his body, for holding on. The tail sucker is toothless and he uses it to hang in waiting until a possible dinner comes within range. The mouth sucker is strong enough to hold him in place during the bloodsucking banquet.

The bloodsucker is a no good cousin of the hard working earthworm. Both of them are annelid animals. They have soft wormy bodies marked with circular segments from tip to tip. The average bloodsucker has a stubby body, three or four inches long. His dark grown skin is mottled with greenish greys to blend with the muddy shadows of his watery hideaway. He swims by wriggling from side to side like an eel. Along each side he has sense organs arranged like a row of tiny buttons. He may have several pairs of eyes.

The wretched parasite also feeds on the blood of fishes and turtles, and will attack horses and other animals that come near the water to drink. When not interrupted, he will gorge his bulging body to twice its normal size. You would expect such a worthless member of creation to have an alias    and so he has. The bloodsucker is known also as the leech.

There was a time when the leech was given a job of sorts. Doctors of long ago thought that human fevers were caused by too much blood in the body. It seemed sensible to use the bloodsucking leech to remove some of the surplus. Modern doctors now know that removing blood from a flushed patient does not bring down his temperature. The leech has lost his one respectable job as a medical assistant, and is back to being a worthless parasite, giving nothing for what he takes.