Female cockroaches living in groups with other females are more likely to have their unfertilized eggs hatch, a research team at Hokkaido University has found, providing a possible explanation for the reason the insect has managed to survive for hundreds of millions of years.

When three female American cockroaches — a species widely found throughout the world — were placed together in a study, ootheca, or the egg case of the cockroaches, formed more quickly than when a single female was observed, the team said.

"It explains well the fact that several female cockroaches will be able to maintain a colony in a more stable manner than a single female cockroach," which can be regarded as a sign of cooperative behavior that is optimized for reproduction seen in other insects like white ants, the research team said in a news release Monday.