When mice heard a sound they thought signaled danger, they moved closer to a familiar companion, according to Virginia Tech researchers. They did not do the same when paired with a mouse they didn’t know. The study, led by Alexei Morozov of the Fralin Biomedical Research Institute at VTC and published in Neuropsychopharmacology, begins to reveal how the brain turns a warning signal into a drive to seek familiar company.

Scientists have long observed that animals gather when confronted with immediate threats such as predators. The new study asked whether a learned warning signal could produce a similar response and, if so, which biological mechanisms might be involved.

Researchers first trained mice individually to associate a tone with a short, mild foot shock. One to two days later, they placed the mice in pairs and played the tone again. Mice that had previously lived together drew closer when the tone played, while those paired with strangers showed no consistent change in distance.