Cat fleas

I have a rental property, the previous tenants had cats, kept the litter box in the unfinished basement, however the cats had the run of the house. The house was vacated 4-5 weeks ago to include cats. We cleaned house top to bottom to include basement....

We had no problem on 2 upper levels of the house but the basement was invested with fleas. While the house was vacant (about10 days)we used off the shelf fumigation (Raid Bombs) for cat fleas. Used this treament 2X, new tenants moved in (THEY HAVE NO PETS). Off the shelf treatment did not work, we have called in professionals (today) they treated and will return in 1 week for follow up.

My question is what should I do regarding current tenants and their belongings. I have done work at the house this past weekend on the upper 2 levels without any bites.

I'm not sure what it is you're asking for help with.

Your current tenants and their belongings? Are they not all in the house?

NOt sure of your question either.

I can tell you that for evey 1 flea you see there are atleast a 100 in different stages, so you may have to bomb the place more then once, they will all hatch at different stages, look up life cycle of fleas