Edmund Brodie of Indiana University and Mathias Kölliker of University of Basel, Switzerland discovered that baby insects signal their mom that they're hungry by stinking up.
To find out, the team looked at parental feeding behavior in burrower bugs (Sehirus cinctus). Adults are about the size of a pencil eraser, and the youngest babes--there can be up to 100 per brood--look like bright red pinheads. The researchers separated the babies into two groups: One got plenty to eat, while the other was underfed. They then collected the volatile chemicals wafting from each clutch. Finally, using a "smell-o-tron," the researchers blew these odors toward mother bugs.
Moms receiving odors from ill-fed babies immediately set to finding more food. Mothers gassed with sated-baby odors, on the other hand, slowed their food search.