Animal behaviour: Mites seek revenge on their childhood foes

Rates of predation by an adult prey on juveniles of a predator species are greater when the adult prey has been exposed as a juvenile to adults of this predator species, suggests a study of three predatory mite species published in Scientific Reports this week.

Animals are routinely categorised as predators and prey, but there are many examples of role reversals, where adult prey attack young, vulnerable predators, suggesting that some juvenile prey can avoid predation and become adults and kill juvenile predators.

Yasuyuki Choh, Arne Janssen and colleagues studied three mite species and show that exposing juvenile prey to adult predators results in behavioural changes later in life. After reaching adulthood, exposed prey tended to kill juvenile predators at a faster rate than prey that had not been exposed. These attacks were specifically aimed at predators of the species to which they had been exposed as a juvenile, suggesting that prey recognise these species. The results suggest that prey may be able to tune their antipredator behaviour based on juvenile experience after an ecological role reversal.