[hal1]

I came home to find someone's cat staring in my front window. Has anyone had any luck or experience with ultrasonic repellers or are they just a gimmick.

I really don't want this to become a thread on how to deter neighborhood cats from sitting on my door step pestering my kitty, as I can search and google this. I just want to know about the effectiveness of motion sensor ultrasonic repellents.

Thanks all