Hi Peter - yes, they do work for us. The first year we owned this house we had about 7 squirrel/like rodents running over the exposed wood beams of the roof structure, at night, making a big racket and not shy or afraid of us at all. Even throwing shoes would not phase them. After installing about five of these things in the various rooms, they left and have not come back since. They did not leave straight away, it took a couple of weeks when we started seeing them less and less until - evicted.