Brill, we used it for our terriers, father and son, they used to fight like crazy as the son tried to get in the father’s bed. the fights were terrible and very stressful for the kids and the dogs. we turn our’s on at night only. there is a light to say when its low. since June (its now dec), we have used only 1 1/2 so its really cost effective. it works right away as well and is a pleasant smell. highly recommend!