Janet Florey, age 12, of Costa Mesa, California, for her question:

Why do bees swarm?

Every summer, this great to do happens in somebody's back yard. A bee arrives, then another and another    obviously in more than the usual state of excitement. In a few minutes the air is crowded with excited bees on the wing. The forerunners were scouts, seeking a suitable spot to establish a new hive. In the meantime, they may decide to set the whole thing down on your apple tree    looking like a big brown football.

During the busy season, the queen bee may lay 2,000 eggs a day    and sooner or later the hive gets crowded. Then she stops laying and a few eggs are prepared to become future queens. The old queen may stay and fight them. Or she may depart before they hatch. She leaves with a teeming swarm of her faithful workers. Together, they start a new hive in a different location. Meantime, back at the old hive, the remaining workers get ready to welcome and tend a new queen.