Damselfly larvae are found in ponds with minnows, and both species are consumed by pike.
 
Mealworms are not a natural prey for the pike but can be experimentally added to its diet.
 
The larvae are exposed to water from a pike that had eaten mealworms (A), minnows (B), or damselflies (C); groups B and C responded by decreasing foraging behavior (feed on brine shrimp), but not group A.
 
Then the larvae are exposed to water from a pike that had been fed mealworms.
 
Groups B and C now have learned, based on experience from the first exposure, to associate pike plus any scent (including that of mealworms) with danger, and this translated into a reduced foraging rate.