Do bees know they're going to die?
Paul asked: I'm sure we have all heard that bees die after they sting you. Is this true? If it is, do they know this and why do they die?
Pollinator and plants researcher Hamish Symington got busy answering this question...
Hamish - This question is highly relevant to me because last Sunday I went to check on my honeybees and got eight stings from a particularly vicious hive. As the bees reminded me, they sting to protect their colony from attack. They don't just sting people, they'll go for any invader, be that a beekeeper, a mouse, a woodpecker, bees from other colonies who are trying to rob their honey, wasps, hornets and more.
Honeybee workers have stings, which are actually made from three separate pieces, a central channel down which the venom flows and a barbed part on either side. When they sting another insect, the sting can go in and out pretty smoothly between the segments of the exoskeleton. But when they sing an animal with thicker skin, like me, the barbed parts catch on the thick skin and actually work as a ratchet to drive the stinger in further.
The force needed to pull those barbs out of the animal's skin is more than the force needed to pull the sting out of the bee. So when the bee flies away, it leaves the stinger. Also, left behind is a little bag of venom which keeps pulsating to inject even more after it's been ripped out of the bee's body.
For a bee, stinging is instinctual. It's what it does when it's faced with a threat, a bit like our own fight or flight response. When the stinger's ripped out, it also releases alarm pheromones which attract other bees and encourage them to sting as well. This is why once I've been stung once, when looking at my bees, I'm often stung many more times soon after.
But death after stinging is just honeybees. Almost all stinging insects have smooth stingers and don't rip themselves apart when they sting. So the bumblebees and wasps you see in the garden can sting repeatedly. Interestingly, queen honeybee stingers are also much smoother than worker stingers and queens can sting humans multiple times without dying.
In practice, they tend to only sting other bees, particularly when they're engaged in a queen fight, which can happen when new queens are raised by the colony.
The only time I've heard of a queen stinging a beekeeper is when he'd been handling many other queens, so perhaps she thought he was a bee. As to the question of whether the bees know that they're going to die, the study of the concept of death within animals is a really interesting and hard to study aspect of animal psychology.
Some scientists argue that bees are conscious, some that they simply follow programmed behaviours during their life. After all, they have very simple brains with only about a million neurons in less than a cubic millimeter of brain compared to our 80 odd billion neurons. They can certainly be trained. It's pretty easy. And I do that regularly in the lab.
But to the best of our knowledge, they don't have an understanding of their impending death if they sting. It's just what they do to defend their colony from marauding beasts like me who want to steal their honey.