They left us a gift. The fleas spread and took over the whole house. The cats suffered the most. They were sleeping and staying close to the floor, and there was no escape from the biting and the itching. We tried to treat them. The internet info suggested the eucalyptus oil. I purchased it, we rubbed ourselves with it and sprinkled on the floor and in the beds and the laundry. It smelled good, but helped just for a short while. We decided to brush the cats with it. Chickie was the first victim. As soon as he felt the oil in himself, he yowled, ran and rolled, like he was trying to get out of his own skin. He peed on the floor right then, I assume, from terrible pain and fear. We washed him immediately.
We washed and treated the carpet repeatedly. The professionals didn't really help. Taka got a little crazy, because he was more sensitive to the whole flea thing. He got up two hours earlier in the morning, washed the floor in our bedroom with a Bissel vacuum, sprayed everything with the latest panacea for the fleas, then took off the clothes and washed them, taking shower afterwords. He found the recipe of the boiled lemon peels, filled the spray bottles with it and started the campaign of spraying everything in sight. Sometimes at night, he would jump off the bed pull off the covers and spray the bed and me in it! Finally, after a few months of this, whether because the lemon peel spray worked or because the hot season, when the fleas are active, was over, the fleas disappeared, the cats stopped scratching and everything returned to normal. For a couple of years after that experience, I react with terror to every little crumb that reminds me of a flea and reach for the lemon peal bottle (that we still keep in the refrigerator) every time I feel an itch.
Despite all the trouble, I feel that we were very fortunate to come by the opportunity to take care of and watch the small animals. They left something with us (except for the fleas), not a tangible thing, but the kind of a wonder before the infinite beauty and wisdom of life. Of course, when Hanah brought in the next kitten that she found (the animals in our area, I think, told each other that there are these dopes who are willing to take them in), I recoiled with horror at the possibility of the new flea infestation. In a few months, though, we had two more cat-tenants messing up the house. But that's another story!