A squirt gun does work as a training device for cats but some people are leary of using it. However, a nicer and actually more effective item is the can of compressed air that you get at computer stores for cleaning the computer. You can quickly teach cats that you don''t want them on the counter, or behind the fridge, or picking on the bird. They hate the blast of air, and even the sound if you are too far away for them to feel it. Don''t spray more than a short blast though, its very cold.