Just an FYI, stay away from flea collars. They don't work and can be dangerous. Last summer we moved into a house that was infested in fleas. Here's what we did:
1. Give everyone with fleas or that might have fleas a bath with regular Dawn dish soap. I did about 3-4 scrubbings each because I'm paranoid
2. Frontline/advantage ALL furry animals, even if they're strictly indoors.
3. Bug bomb the house. Alternatively, get a pest control company to do it for you.
4. Deep clean!! Wash sheets, blankets, everything the infested animals have come into contact with. Steam clean anything that can't be washed (couches, chairs, mattresses, etc).
5. Use frontline/advantage religiously each month. This will prevent a reinfestation.
And that's what worked for usFlea free for almost a year!!!