The Smell of Death (broadcast Friday, September 18th, 2009)

Photo by Flickr user sburke2478.

A specific blend of fatty acids signal death or injury to a variety of animals, providing a warning to others of the species. Oleic or linoleic acids, compounds released by the cells of some animals soon after death, served as a death signal, or 'necromone,' in insects such as ants, cockroaches, and caterpillars, as well as in woodlice and pill bugs, which are crustaceans. Many of the species aggressively avoided areas treated with this 'smell of death.' The ants used the chemicals to identify deceased ants to be removed from the nest. We'll talk with David Rollo, author of an article about the work in the journal Evolutionary Biology.