Melvyn Bragg and guests discuss how members of the same species send each other invisible chemical signals to influence the way they behave. Pheromones are used by species across the animal kingdom in a variety of ways, such as laying trails to be followed, to raise the alarm, to scatter from predators, to signal dominance and to enhance attractiveness and, in honey bees, even direct development into queen or worker.

The image above is of male and female ladybirds that have clustered together in response to pheromones.

With

Tristram Wyatt

Jane Hurst

and

Francis Ratnieks

Producer: Simon Tillotson