I can't imagine any safe way. Anything that kills fleas will probably harm people to some degree.
Fleas usually can't live without food. What are they eating when nobody is there?
What is in the place now? Are they living in furniture? carpets?
Note that you are within your rights to back out of an agreement based on this new info and get any deposits back.
I would ask that the landlord have any furniture and carpets replaced, and a thorough cleaning with hot water or steam or whatever they can do to whatever is there. If he doesn't agree, then back out of the agreement.
Sounds like the place is really infested. My cats get fleas in the summer, but i would never see as many as you saw in such a short period of time.
Fleas usually can't live without food. What are they eating when nobody is there?
What is in the place now? Are they living in furniture? carpets?
Note that you are within your rights to back out of an agreement based on this new info and get any deposits back.
I would ask that the landlord have any furniture and carpets replaced, and a thorough cleaning with hot water or steam or whatever they can do to whatever is there. If he doesn't agree, then back out of the agreement.
Sounds like the place is really infested. My cats get fleas in the summer, but i would never see as many as you saw in such a short period of time.