German cockroaches appear to be more social animals than previously thought
tags:
Newborn German cockroaches use pheromones in cockroach feces to identify members of their own colony and form a kind of social bond, a discovery that could be used to improve pest control efforts.
Scientists compared neonate cockroaches that had been allowed to consume their colony's feces and were exposed to fecal odors with neonates that had not engaged in coprophagy. German cockroaches are born with no gut microbiome and rely on eating feces from a collective fecal pile within their cockroach "aggregation" to gain the microbes and fecal nutrients they need.
Neonates who ate from the aggregation's feces after hatching displayed an affinity for the specific pheromone present in that aggregate, while neonates without any microbiome—known as naïve neonates—showed a much broader, less focused array of interests.
Using pheromones against infestations
"This finding could be used to help control cockroach infestations," said Ayako Wada-Katsumata, a principal research scholar in North Carolina State University's Department of Entomology and Plant Pathology and lead author of the paper published in the journal Proceedings of the Royal Society B: Biological Sciences.
"What we've found is that aggregation pheromones are extremely important in how these cockroaches find each other and group together," Wada-Katsumata said. "Because the aggregation gives these neonates everything they need early in life, they have little reason to leave it, which makes traps and insecticidal baits less effective.
"If we can develop an aggregation pheromone that works across the entire species, we could make traps and baits far more effective and make it easier to control populations in places like residences, hospitals and restaurants."
Cockroaches show stronger social ties
Beyond the practical applications, this research also unveils a fundamental misunderstanding about cockroach social structures, said Coby Schal, co-author of the paper and the Blanton J. Whitmire Distinguished Professor of Entomology at NC State.
"We think of cockroaches as being subsocial, in that they are not completely solitary but also do not exhibit the kinds of group behaviors that bees or ants do," Schal said. "The use of fecal aggregation pheromones to recognize their natal group is a behavior that mirrors that of social insects like bees, wasps, ants and termites, which typically use body odors instead of fecal odors to recognize nestmates. Both groups of insects share a similar mechanism that involves learning and memory of their colony's unique odor, but the anatomical source of the pheromone is different."
This behavior implies a greater capacity for social structure and learning than has often been attributed to the German cockroach, Schal said.
"What we're seeing here is a capacity for learning and memory retention that is often thought of as being beyond that of an insect as primitive as the cockroach," he said. "Cockroaches have evolved their own twist on forming kin bonds."
Publication details
Ayako Wada-Katsumata et al, Group recognition in the German cockroach, a subsocial omnivore, is based on faecal odour preference that is modulated by coprophagy, diet and learning, Proceedings of the Royal Society B: Biological Sciences (2026). DOI: 10.1098/rspb.2025.3042
Who's behind this story?
BA art history, MA material culture. Former museum editor, paramedic, and transplant coordinator. Editing for Science X since 2021. Full profile →
Bachelor's in mathematical biology, Master's in creative writing. Well-traveled with unique perspectives on science and language. Full profile →
Citation: German cockroaches appear to be more social animals than previously thought (2026, August 5) retrieved 5 August 2026 from https://phys.org/news/2026-08-german-cockroaches-social-animals-previously.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.