It started a month ago for me.
I shouldn't let Hoggie out but he only gets 15 minutes a day where he's really free. (with me watching for coyotes)
So here's something that costs about $10 to make that gathers all the fleas at night. I have one at each end of my room. The fleas think the heat from the 4watt bulb is your pet. They jump toward the heat and fall on the sticky paper.
Judge For Yourself. This one was made a month ago.
When one side gets bad, you peel the paper off the other side, place the peeled paper on the buggy side and, turn it upside down.
PS For kittens put 1/4" screen around the sides with a flap you can open to change the paper or the bulb.
MAKE GREAT GIFTS
You can buy pre made units online but they are of paper thin molded plastic and are destroyed if anything falls on them. (like an 8oz bottle of water)