I'd suggest checking to make sure you have fleas in your house in the first place. (You'll see them if you do!) If you have them, I'd have someone come to spray. They will guarantee their services and say that if you see fleas within I think it's 30 days they'll come back and spray again. From past experience, wait 3 weeks, and call them back and have them come again whether you do or not. Trust me on that one! You can Google the life cycle of the flea and you'll see why. (When they spray it doesn't get all the life stages--misses one or 2. That's why I say to have them come back.) Last summer it rained so badly here that everyone was getting infested with fleas. I only had cats then, and they are indoors only cats, but the fleas just came inside!! My landlord had to have it sprayed, and then was angry that I saw fleas 5-6 weeks after they'd been there because he had to pay to have them come back.
You can find a spray and do it yourself, also, but I think if it doesn't cost too much, it's just better to have a professional do it (especially since they guarantee their services.)
Also, watch your baby for tapeworms. Biting at and actually eating a flea is how dogs/cats get tapeworms. In fact, a flea is the tapeworm's middle man...the flea has to have eaten the tapeworm eggs in order for them to be able to hatch inside your pet. After you're sure fleas are gone, you can worm him with something like safe-guard (
Dog Worms | Eliminate dog worms with Safe-Guard Canine Dewormer | Fenbendazole) because it gets rid of tapeworms too--you do have to do it 3 days in a row, though.