Rats raiding trash cans is one thing. Rats leaping into the air to snatch bats out of the sky is something else entirely. That is exactly what researchers in northern Germany documented at a pair of busy bat hibernation sites, using infrared cameras to capture behavior that had never been recorded in such detail before.
In Short
- Scientists in northern Germany filmed brown rats hunting bats at two urban bat hibernation sites.
- The rats used two main strategies, ambushing resting bats and jumping up to catch those in flight.
- The study is the first systematic documentation of rats preying on bats in European cities.
- Researchers say the behavior could worsen pressure on already vulnerable bat populations and may have disease implications.
How The Discovery Was Made
The research team set up infrared and thermal imaging cameras at two bat hibernation sites in northern Germany, Segeberger Kalkberg and Lüneburger Kalkberg. These locations host thousands of bats that use caves and rock crevices as winter refuges. The cameras recorded activity over several years between 2020 and 2024, mostly to monitor bats.
What they did not expect to see was a different mammal entirely. Review of the footage showed brown rats (Rattus norvegicus) repeatedly attacking bats that were leaving or entering the hibernation sites. In some clips, rats positioned themselves near bat exit points and waited for an opportunity. In others, they appeared to patrol ledges and cave floors looking for resting animals.
Two Rat Hunting Strategies
According to the published study, the rats relied on two main hunting strategies:
- Ambush attacks: Rats waited near exit holes and launch points, then pounced on bats as they crawled or fluttered past.
- Leap and grab: In some of the more surprising clips, rats stood on their hind legs and jumped to intercept bats in midair, pulling them to the ground.
After a successful capture, rats were seen dragging the bats away to be eaten. The behavior was not a one-time fluke. Researchers recorded dozens of attacks at both sites, which suggests that at least some rats have learned that busy bat colonies are a reliable food source.
Why This Matters For Bats
Many European bat species are already under pressure from habitat loss, climate change, and human disturbance. Roost sites that host large winter colonies are considered especially important, since disturbing hibernating bats can cause fatal energy loss. The discovery that rats are actively hunting at these locations adds another layer of concern.
Because the rats targeted bats near exits and entrances, they may be picking off individuals that are already stressed from cold weather or human activity. If the behavior spreads or becomes more common at other sites, it could contribute to population declines, particularly for species that congregate in tight spaces during hibernation.
Health And Disease Questions
Bats and rats can both carry pathogens that affect humans and other animals. Any new interaction between the two raises questions about whether diseases might jump between species more easily. The authors note that more work is needed to understand the health side of the story, but they do point out that urban environments are creating unusual overlaps between animals that once had very different habitats.
In Short
- Infrared cameras in northern Germany caught brown rats hunting bats, including midair attacks.
- The footage shows repeated predation at major bat hibernation sites, not just a one-off event.
- Scientists are concerned about added pressure on bat populations and the possible disease implications of close rat bat contact.
Sources
- Global Ecology and Conservation – “Active predation by brown rats (Rattus norvegicus) on bats”
- Phys.org – “Caught on camera: Rats snatching bats from the sky at city bat roosts”
- Smithsonian – “Rats Are Snatching Bats Out of the Air and Eating Them”
- Mongabay – “Europe’s under pressure bats face ‘astonishing’ threat”
- Yahoo News – “Scientists warn of new pandemic risk after rats filmed hunting bats”