Ambush has worked so well for my animals. It works really good at keeping flies an bugs off my livestock, and I have found it work EXTREMELY well at killing and keeping fleas off my dogs. I spray my dogs and rub the spray in until their fur is wet, and the fleas start dying in minutes. It has been working on keeping ALL fleas of my dogs for about 3 weeks and still going with just one spray down (this was the first time I tried it, 3 weeks ago, and it's still working wonders). There hasn't been one flea on them since. I live in the country and the fleas were really bad, but not anymore!