This happened when I was in my mid-twenties or so...
Anyone who has pets has fleas, there's no way around it... and I am extremely allergic to flea bites. I can even feel exactly where the little buggers are feasting on me. And since you can't smash them or drown them, I have perfected the art of picking them off between my thumbnail and forefinger... and then crushing them between my 2 thumbnails. I get to see how much of my blood they got (ha!!) while I watch the welt grow in that spot... so it serves them right!!!
A friend of mine back then was telling me about how ammonia is supposed to drown/kill them, so he keeps a jar of it handy just for that purpose when he catches them. I never tried it myself, but I took his word for it.
One time I was over at his place with a few of our friends and someone noticed the little jar of clear liquid, with some tiny black specs floating around in it, and asked him what it was. So he proceeded to explain his whole flea killing theory to everyone in the room... while one girl just sat there staring at the jar with a puzzled look on her face.
Finally she spoke up and said, "There's just one thing I don't understand... how do you get them to jump in there in the first place???"