for National Geographic News
Coercionnot altruismis what keeps worker insects from reproducing, a new study suggests.
The finding paints a more complex and somewhat darker picture of insect behavior than scientists had previously suspected.
Worker bees, ants, wasps, and termites share food with their nest-mates and collectively raise their colonies' young.
Rank-and-file workers, who are the queen's daughters, usually don't lay eggs, even though they have ovaries.
Scientists have sought for decades to account for the workers' self-denying behavior.
They originally suspected that workers freely choose to help their mother with her other offspring, because compared to reproducing on their own, it's a more efficient way of propagating their genes.
But the new study suggests that a typical insect society is not an obliging commune, as that theory might imply. On the contrary, says Tom Wenseleers of the Catholic University of Leuven in Belgium, it resembles a miniature dictatorship.
Outside the royal chamber, reproduction is forbidden, and unauthorized eggs are terminated, the biologist explains.
"It's kind of a police state, really," he said.
Sisters and Daughters
In 1989 Francis Ratnieks of the University of Sheffield in England discovered that honeybee workers eat each others' eggs.
Since then, scientists have observed such egg-killing behavior, called policing, in numerous other insect societies.
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