Reply #1: I took in a stray cat once that had fleas.

[trotsky]

I lived in a smallish apartment at the time. Fought the fleas for weeks. What finally vanquished them was a multi-pronged attack:

1) Bathe the animal(s) - I had two cats.
2) Dip them.
3) Put them in a carrier, set off some flea bombs, and leave for several hours.
4) Repeat the whole process within two weeks - fleas are impervious to chemicals during part of their lives, so any that were at that stage the first time may be emerging by the 2nd time, and you'll get 'em.

And definitely change groomers - yikes!