I would never waste my money on this product, I used it once on 3 cats, I used it 2 days before one cat was going to the vet to be neutered, I dropped him off, let them know he had just had flea drops applied 4 days prior (so they would not use anything on him and over dose him). I went back a few hours later to pick him up, to be told that he was INFESTED with fleas , When I got home I inspected my other 2 cats, yep they were too! so I (and they) had to wait a month to get something else, because I did not want to mix products, Following month, I bought a brand off Drs Foster and Smith, that can be bought at the vet (but it was cheaper online), applied it, and checked them the following morning no fleas! I make sure to let me friends and family know not to use this product. It does not get rid of fleas, my cats were not infested when I applied it, I groom them daily, and I only saw 2 fleas on them and got none from their flea comb, I honestly think this product made the fleas hatch! because they were miserable the entire time this product was on them. My cats are adults (4 and 3 yrs old) I've had the two oldest since they were 4 months old, had the youngest since birth, they never had a flea infestation before and they do go outside in a enclosed kennel made just for them. So this cat paren't wills top trying to save a penny, and cut corners, and stick to the flea drops that work, yes they may cost more, but in the end they work! This stuff does not work!