How do social wasps and bees communicate danger?

NARRATOR: Well, folks, you asked and were answering. That's right, we heard you. This week, we're answering a burning question [? Kay Drudera ?] had for us. Why do wasps become more aggressive when you kill one of their friends? Well, here's why.

SOPHIA CAI: It's not so much that you've killed a wasp, but that you've threatened other wasps or their wasp home. Both social wasps and honeybees use what are called alarm pheromones to warn their buddies about nearby dangers. Pheromones are chemical messengers that travel through the air and affect other animals behavior.

So if a hive or nest is disturbed, guard wasps will send out these small molecules to rally the troops. Then the wasps will all swarm out of the nest and attack the intruder.

These social insects, like bees and wasps, all have molecularly different alarm systems. The first molecule identified in the honeybee mixture was isopentyl acetate, also known as banana oil. Ask any beekeeper and they'll tell you, stressed out bee colonies will often smell like bananas, a telltale sign they're ready to attack.

So how can you break up the fight? Beekeepers often use smoke from a special dispenser to disguise the pheromone smell and trick the bees into not attacking. But to avoid getting stung altogether, better to leave them alone or if you must, call a professional.