FROGS learn the scent of danger before they hatch, which may give tadpoles a head start in evading predators.
Animals learn that a smell or sound is a warning if it accompanies something dangerous. Maud Ferrari at the University of Saskatchewan in Saskatoon, Canada, and her team tested whether wood frog eggs could be primed to detect a predator’s scent.
The team bathed the eggs in water that had previously contained fire-bellied newts. Half the eggs were also given a whiff of danger, in the form of an infusion of crushed-up tadpoles, whose death is marked by chemical signals. After…
