Cat Deterrent

[Stephen Mroszczak]

Has anyone tried this against cats?  We've got a couple that are starting to prowl through our backyard at night and make quite a racket.  I have a couple of commercial Ultrasonic devices that we have put in our backyard that seem to have helped.  The problem is, they are on the ground so don't seem to trigger when the cats run along our fence, and they are quite expensive.  I'd like to cover our fenceline with a few of these to scare the bastards off.

However, before I turn the backyard into a scene from the Terminator, I'd like to know if I need any modifications to deter cats.  Are there any frequency and power combinations that have worked for anyone?

Thanks,

-Steve