The buzz: The science of swarming,

Bees break off from their hives and light out for a new home for several reasons.

“It could be that it’s too congested,” says Toronto Bee Rescue founder Peter Chorabik. That’s the main one. “It could also be they just don’t like their home, or it could be that they’re sick.” The process — called swarming — is typical in the life cycle of every hive. “It’s how the bees spread their genetics.”

Generally, the worker bees elect to up and leave, taking the old queen with them.

A new queen then establishes her dominance back at the original digs, while 15,0000 to 30,000 of her kin take flight from their native land.

During migration, it’s not uncommon for a few stragglers to be left in the dust, with some bees always away foraging and scouting at any given time.

“A bee colony is like a super-organism,” says Chorabik, whose organization rescues about 15 swarms a year (Chorabik himself has 120 bee colonies — totalling more than 4.8 million bees).

“A bee can’t survive when it’s on its own; it can only survive when they’re together,” relying on the collective pollen and honey stores for nourishment.

Canadian beekeepers reported a loss of about 200,000 colonies during spring 2013.

But the numbers are on the rebound, with a burgeoning urban beekeeping movement keeping the key pollinators in constant supply.