Cats Are Silent Assassins

Cats are very efficient little killers. With the amount of domestic cats in the US, that's a huge body count of birds, lizards mice and other critters that were in the wrong place at the wrong time. Behold the infographic.
The particularly interesting part to me is that one cat killed off an entire species of rare songbird by himself.

 

How in the world do they calculate how many animals are killed by housecats every day?

And are those only inside cats or does it include ones that go outside, too?

I love that last set of pictures!

 

I often wonder how statistics like this are calculated. They might be counting housecats that go outside because of the part that says "When cats are allowed to roam, 44% hunt."