You've politely told your little predator, "No, thanks." But your cat insists on showering you with gifts of dead mice, birds, or lizards. Bringing you dead animals is normal, but it's best to keep your cat inside. Prowling cats can have a devastating impact on ground-nesting birds and hunting can also be a source of parasites and bacterial disease. Instead, give your cat toys they can hunt for inside. It will give them an outlet for their predator behavior -- and keep wildlife safe.