DOWN in the mud of ponds you will find a very strange larva. It is sometimes called a "rat-tailed maggot," because it seems to have such a very long tail at one end of its fat, worm-like body. This "tail" is really much more important to the larva than an ordinary tail would be, because he uses it to bring oxygen to his body from the surface of the water. You know how one part of a telescope fits into another. The parts of the air-tube of a rat-tailed maggot appear to fit together in much the same way. Thus the larva can shorten or lengthen his air-tube. This is what he is doing when he seems to be draw­ing in his tail or pushing it out.

This little animal is the larva of the drone fly. Many insect larvae which use oxygen from the water around them would soon die if placed in stagnant ponds, but because of his air-tube, the rat-tailed maggot can live in muddy or stagnant water where there is not much oxygen. He creeps along, feeding on decaying vegetation or animal matter, and uses his air-tube tail to bring oxygen from the surface.

After he has grown and developed, the drone fly larva changes into a pupa with a hard, outer skin which protects the soft inner parts of the animal while he gradu­ally develops into a fly.

When the fly inside the pupal case is ready to live in the air, it emerges as a two-winged insect. Drone flies, sometimes called flower flies, are one-half inch long, or longer, with broad heads and large eyes. They eat pollen and nectar, so you will find them near flowers.

When they are flying, drone flies are sometimes mistaken for bees. When they are at rest, it can be seen that they have only one pair of wings. Bees have two pairs.