I don't like to put toxic pesticides in the house that I, or my pets, will be exposed to.  But, I have cats and even though they are inside cats, it seems like every summer, we have a flea outbreak--particularly in the carpets.  These things attract fleas like crazy.  The combination of the white paper with the light really attracts them.  Sometimes when I am changing the sticky pad, fleas will jump on the new pad before I even get it into the container. Sometimes, I just wave the pad over the carpet, and fleas will jump up and hit it.  They are REALLY sticky so you have to be careful that other critters can't get to it.  Unfortunately, a lizard managed to get to one of these even though it was in the back of the house.  Also, once in a great while a cat will manage to get one stuck to him/her and it is a pain to get the pad off of them.