Do Ant Brood Pheromones Exist?

A brood pheromone is a chemical or mixture of chemicals released by immature stages that elicits a behavioral response in conspecific adults. The current literature devoted to brood pheromones in several ant species does not prove the existence of such a pheromone or even of brood-specific chemicals. The possibility of a food response or a nestmate recognition response, two of the most confounding factors, has not been eliminated. Two alternative hypotheses involving brood behavior, morphology, cuticular chemicals, and associative learning are proposed.