Dorothy Stamen, aged g, of Eureka, I11., for her question:

What makes a bee hum?

The hum of a bee may remind you of a lazy summer afternoon. For then the bees are busiest among the flowers and clover. The droning buzz may fit your mood of lazy summertime. But the lazy sounding hum is not made by a lazy bee.

The busy bee makes her hum with her wings. They move so f ast that you can hardly see them, when she is flying, all you can see is a hazy blur where her wings should be. A bird beats the air with its wings.. You can watch them flap. If you are close enough you can even heir them.

Beating wings set up vibrations in the air. And air vibrations wake sound. You can count the wing flaps of a bird ‑ but not of a bee. She beats her wings at the rate of 400 times each second‑which i$ much too fast to count, The vibrations from these wings are so close together that they blend into a steady hum.

The little bee has to flap her small gauzy wings that fast to keep her plump body in the air.