A new study published in the latest issue of the journal The American Naturalist, revealed an unfamiliar behavior adopted by a species of beetles known as "burying beetles" to feed their offspring. They scout for a dead mouse or bird, dig a hole and bury it, pluck its fur or feathers, roll its flesh into a ball and cover it in goop—all to feed their future offspring.
Now scientists think that goo might do more than just slow decay. It also appears to hide the scent of the decomposing bounty and boosts another odor that repels competitors.
"It helps them to hide their resource from others. They try to keep competitors away," said Stephen Trumbo, who studies animal behavior at the University of Connecticut and led the new research, in a report published by The Associated Press.
The beetles—called burying beetles—aren't the only creatures who try to deceive their competitors or prey with subtle, sneaky tactics. Large blue butterflies, for example, will imitate certain sounds to manipulate ants. Corpse flowers produce rotting odors to attract insect pollinators that feed on decomposing matter.
"Knowing these interactions is important to understand how these beetles deal with fierce competition while looking for corpses, and using it to provide food," said Alexandre Figueiredo, a biologist at University of Zurich, who was not involved in the new study.
Burying beetles and other things that feed on dead animals—including vultures, opossums and maggots—compete with each other to track down carcasses. Competition is stiff even among burying beetles, which use special antennae to detect the remains from afar.
Burying beetles are relatively large, about an inch long, and black with orange markings. The gut secretions they spread on a carcass are antibacterial, and slow down decomposition. The research team wondered whether they also prevented rivals from picking up the scent.
To find out, they collected the gases wafting off dead hairless mice preserved by a kind of burying beetle that is found in forests across North America. The researchers then compared the gases to those from untouched carcasses. The beetle-prepped ones gave off much less of an onion-smelling compound that usually attracts competitors. They also discovered an increase in another gas from decay that's known to deter other insects that feed on dead animals.