You just need to put the animal on a piece of newspaper and pat its fur, and then clean up everything that has fallen with a paper towel. Flea dirt will turn red when wet. I also didn't understand how my dog could have fleas until I talked to a specialist. He said that we don't kill all the parasites completely, so they multiply very quickly, causing discomfort to my pet. After searching for some information on the Internet, I came across an article about large selection of flea collars for dogs, and decided to order it. In the end, I did not regret the purchase, because now my favorite cat does not suffer from scabies after a bite .