Give them a panadol and bury one under each new bush, tree or buried treasure.

?

Our seven cats are all kept in the house to prevent them from preying on birds and other creatures outdoors, as well as for their own protection. Any small creature that walks or crawls or flies into the house has little or no chance of survival; we have often found mice, voles, snakes and even a flying squirrel lying dead on the floor, much to our dismay. The intense interest three of our cats have in watching the birds at the feeder, and the throaty growls and lunges they make while doing so, are evidence enough of what they would do if allowed outdoors.

They are predators par excellence.

A cats natural instinct is to hunt.

I have always been a cat lover to the point that I refuse to trap my cats indoors if they choose to want to go outdoors. About 2 years ago, I was given a 9 year old de-clawed cat that had never been outdoors and after about 3-4 months, she decided she wanted to go outside, so I let her. Ever since she has been leaving, on average, 2 mice per night at my front door step. One time I found an entire family of about 5 mice at my door step. I could never kill a mouse myself but that's what cat's do and to deprive them of there natural instincts is cruel imo.

I also had a cat, named psycho, that would kill rabbits and squirrels. I didn't agree with it but I sure wasn't going to deprive him of his freedom for doing what cats do...

@djkraz: We aren't talking about feral cats that live outdoors and eat what they catch in order to survive. We are talking about pet cats that are presumably fed and do not have to kill to eat, but kill anyway due to their predatory nature. IMO it is irresponsible to let a pet cat roam outdoors freely, where it is exposed to the dangers posed by traffic, disease, parasites, attack by dogs or other animals, etc., all because it instinctively wants to find creatures to kill. It is also irresponsible to allow cats or other companion animals do whatever they want to do, even if it means killing countless birds, small mammals, reptiles and amphibians. There are leash laws for dogs. Why not for cats??