I just wanted to add what has worked for the last 2 years for me. 3 outside dogs. Apple cider vinegar, one cap full (maybe a teaspoon) every night with their food. Flea free. Years before feeding vinegar dogs had problems with fleas. For inside a house I have heard putting a night ight on and putting a bowl with water and dishsoap. Fleas are attracted to the heat given off from the light and end up in the bowl of soapy water. Never tried it but makes sense.
