While we humans go about our daily conversations (often on cell phones), we don't realize that the whole world is talking and listening, including insects and plants.
Predatory beetles can detect the unique alarm signal released by ants that are under attack by parasitic flies, and the beetles take advantage of this: they use those overheard conversations to guide their search for safe egg-laying sites on coffee bushes. It's almost as if overhearing a crime being planned caused one of us to get in there first, and take all the valuables.
These ants patrol coffee bushes and emit chemical alarm signals when they're under attack by flies. Ants and other social insects communicate using chemicals called pheromones. Researchers noticed that pregnant lady beetles intercept the ants' alarm pheromones, which let the beetles know that it's safe to deposit their eggs.
The insects are listening to each other, so WE need to "spy" (NOTE: Subscribers can still listen to this show) on them to learn what they're telling each other, ESPECIALLY if we like a nice cup of coffee in the morning!