Inside your sweet little house cat beats the heart of a mass murderer, scientists say.
While it's no secret that cats are predators, a new study published this week shows just how deadly they can be in the wild.
Cats will eat more than 2,000 different species, including birds, insects, reptiles, and mammals.
They're such skilled hunters that they pose a threat to the biodiversity of the North American bird population.
Cats have even been linked to more than 60 species extinctions around the world.