Invasive Rats Launch Deadly Ambush on Europe’s Vulnerable Bats

European bats already struggling with urbanization and habitat loss now face a shocking new threat: invasive brown rats that deliberately ambush them during flight at their winter hideouts.

Researchers using infrared cameras documented this unprecedented predator behavior at two major bat hibernation sites in northern Germany. The brown rats position themselves strategically near cave entrances and rocky crevices, waiting to intercept bats as they enter and exit their winter roosts. This marks the first recorded evidence of invasive rats systematically hunting bats at continental European hibernation sites.

The attacks are occurring at critical refuges that shelter thousands of native bats, including vulnerable species like Bechstein’s bat and the pond bat. “Because bats in Central Europe are increasingly threatened by human activities such as urbanization, light pollution, and road construction, it is becoming harder for them to reach their winter hibernation sites,” explains Florian Gloza-Rausch, a bat researcher at Berlin’s Museum of Natural History who co-authored the study.

Brown rats, originally from Asia, colonized Central Europe in the 18th century and have since become ubiquitous in cities and towns. While invasive rodents are known bat predators on islands, this urban hunting behavior represents a disturbing escalation that could push already stressed bat populations toward further decline. The discovery highlights how invasive species can exploit and compound existing environmental pressures, creating unexpected ecological disruptions in urban environments where wildlife increasingly seeks refuge.