I have no pets but I found millions of fleas in my basement.

I could not find where to post the question about fleas. I did not posted in pets because I have no pets. I do not know how did I get this tiniest bugs but persistent. My husband bought two 32 oz of some spray in Home Depot. The fleas were still there. He went and bought a two gallon and sprayed the whole house. The fleas are less but they are still there.

Anyone can help. Before to call an exterminator than in this area is very expensive we want to try to cure this infestation by ourselves. Does any body knows what product to buy. I googled the question but most of the sites talk about pets. If someone knows any information I would like to know the name of the product and where to buy, or if someone knows a home based formula I will appreciate give me the information.

Thank you.

Rosa