HAMILTON, Ontario, Sept. 15 (UPI) -- Canadian scientists say they've discovered the smell of recent death that repels living relatives of insects is an ancient universal warning signal.
The researchers, led by McMaster University Professor David Rollo, said the death odor emanating from corpses of animals, insects and crustaceans is produced by a blend of specific fatty acids and functions to avoid the spreading of disease by repelling the living.
Rollo said he and his team made the discovery while studying extracted body juices from dead cockroaches.
"It was amazing to find the cockroaches avoided places treated with these extracts like the plague," he said. "Naturally, we wanted to identify what chemical was making them all go away."
The team eventually identified the specific chemicals that signaled death. They subsequently discovered the same fatty acids not only signaled death in ants, caterpillars and cockroaches, they were equally effective in terrestrial woodlice and pill bugs that are actually not insects but crustaceans related to crayfish and lobsters.
"Recognizing and avoiding the dead could reduce the chances of catching the disease, or allow you to get away with just enough exposure to activate your immunity," Rollo said.
The findings appear in the journal Evolutionary Biology.