The other day while in the pet shop I came across the “Liberator” cat collar, I had previously mentioned CatAlert, but I found this one which seems less bulky to me, and works on a leap activated basis. At around £10 I thought this was pretty reasonable in price. Rolf Harris has apparently endorsed it - not that this should be the thing to sway you, more the fact that over 70 million birds are killed in the UK every year by cats alone.

As I have previously stated, owners need to become proactive and do something positive, how many times do we have to get to the point where fines need to be enforced and new legislation brought in before people decide to lose their apathetic attitudes … It will get to the point where cat owners will be up in arms because all cats will be required to be confined indoors, which as you know is what I think should be the case anyway.

What a lot of cat owners say is that their cat cannot stand wearing a bell and will go manic if made to wear one, so this could be a good alternative. As quoted on the “Liberator” cat collar:

Cats ambush or stalk prey to get as close as possible before launching attacks. Teeth and claws aside, its cats' propulsion abilities that gives them the hunting edge. When cats launch on live prey, they generate a substantial force of inertia. This action causes a motion sensor to trigger an audio visual alarm at the beginning and during the entire strike distance. In an explosion of common sense, Liberator® uses the force of inertia to activate the alarm. In this way, Liberator® supplies a clear pre-attack warning and provides prey with an opportunity to escape. Without placing any physical or physiological restriction on the cat (save the annoyance of yet another prey victim escaping but they'll get over it) Liberator® sabotages the "strike action". Liberator® includes a light which activates with the alarm. At night, if the cat has been allowed to be outside or has escaped, this exposes the predator and the direction of the attack. 

Sounds good to me! Also, I am sure a lot of owners get fed up with hearing a bell rattling in their ears so this will not be invasive to humans either.