Reporting for Mother Jones, Deanna Pan writes about a new research project at the University of Georgia which is equipping house cats with wearable kitty-cams to find out exactly what they get up to when no one’s around. The “shocking truth,” she writes—it’s not actually that shocking—is that a decent proportion of the cats spend their free time hunting, killing around two animals a week. Add it up, and it’s likely that house cats are “killing more than 4 billion animals annually.”

Pan talks to one appalled owner: Having seen just video evidence of how predatory her house cat Ursa really is (“she hadn’t ripped the bird apart yet, but it was clear that the bird was in great distress”), Evet Loewen equipped her cat with a bell to warn potential prey. If you want to be similarly taken aback—or perhaps just want to see just what an impressive hunter your cat really is—you owe it to yourself to check out the video gallery on the “KittyCam” website. The first-person videos of a cat jumping a fence and warning off a dog are particularly great.