Some of you guys need to get a cat lol.

My friend had one and a mouse was running around, so the cat started chasing it but didn't seem to want to kill it. The cat's owner started beating the mouse to death with something, and holding the cat by the scruff of his neck yelling, "You see? That's what YOU are supposed to do!"

Apparently, cats do not know to bite off the heads of rodents unless the mother cat teaches it as a kitten.

Or, you could get a Jack Russell terrier - they'll always go after mice and rats and won't give up until the animal is dead.