Ants are tidy creatures. Workers quickly dispose of garbage and feces in the interest of keeping their nest neat and clean. Should a fellow ant pass on to that great ant hill in the sky, its comrades are just as quick to remove the corpse from their home. How ants determine that a fellow ant is dead has long puzzled scientists.
Argentine ants emit a distinct odor while living. Soon after death, these chemical signals disappear.
Photo: Flickr user Matthew Townsend.
Entomologist Dong-Hwan Choe, of the University of California-Riverside, wondered how chemical signals from the deceased ant might broadcast its demise to the ant colony. He and fellow researchers studied the chemical composition of the cuticle of Argentine ants, Linepithema humile.
Choe's team discovered two chemicals that are present in living ants, but quickly dissipate when the ant dies. The finding suggests that ants can smell death, or rather, smell a lack of life. As ants go about their business in the nest, they smell each other. Any ant lacking the distinct odor of the living goes on the trash heap.
More on How Ants and Other Insects Smell:
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Source: Dong-Hwan Choe, Jocelyn G. Millar, and Michael K. Rust. Chemical signals associated with life inhibit necrophoresis in Argentine ants. PNAS.org.