I don't know if this is really all that strange, but in Des Moines Iowa there is an ongoing epidemic of bedbugs; and they would spread like lightning through the (otherwise lovely) senior apartments where I lived. So every day almost, I would check settee/chair/EVERYTHING for their nasty little traces. I read up on bedbugs, and got pretty good at detecting them...you see where they have traveled because of their little feces...and they love soft settees and such.
So that is my answer for you; bedbugs.
AND, if you ever post a question asking for our favourite trivia fact, I often answer that one with, "Did you know bedbugs will travel 200 feet in search of a blood meal?"
Some people don't react to their bites; I do, and they escalate in pain/itchiness/burning for about three days and then very slowly taper off...I have had a zillion bites like this, they are very characteristic:
Here you go, you can see the ingested blood in their translucent abdomen.