Andy Steffy, age 9, of Lancaster, Penna. for his question:

How does a fly buzz?

A fly buzzes with his wings. At top speed, these little bits of gauze can beat 1.80 times a second ‑ so fast that all we see is a hazy blur. This movement fans the air, making it vibrate with the well known buzzing sound.

Members of the fly family have only ono pair of wings. Instead of a second pair, they have two little flying sticks, one on either side of the body. They are called halters and when the wings move the halters also move.

It is thought that the fly's halters act somewhat like gyroscopes, They keep the body balanced in flight and may also help with the steering. Each is fixed in a socket and controlled by microscopic newel and muscles. Flies belong to the insect family _ptera ‑ the two winged ones. Most flying insects have four wings ‑ but flies manage to make a great nuisance of themselves with only one pair.