I can tell you that it took an exterminator to get them out of my house. Over the counter powders, sprays, flea dip (for the cats), flea bomb (which meant a night in a hotel), none of it worked and added up, it all cost a lot of money. If you vacuum, you have to get rid of the bag every time. Trust me, call an exterminator. I’ve said it before and I’ll say it again, fleas are what brought me to Fluther. I had fleas in the house ten years ago, with a newborn baby here, and I was stressed out from the fleas. I was googling and learning about fleas, the flea life cycle, flea gestation, flea eradication, etc, and I found Fluther in the search. To answer your question about fleas living on a human, they’ll jump on, bite and jump off. They’re not interested in human blood. Fleas want cat or dog blood.