I got paid for being a lab rat in the eighties, an allergy doctor developing tests for specific allergies. I made several hundred dollars, plus some free appointments with the doctor for both me and my daughter, which were probably worth several hundred more, but the hassle it was to me, I earned the money, blood pricks and scratches, time in the office for the study's benefit, not mine, going weeks without eating _anything_ of the particular substance studied at the time (did you know that some corn product is or can be in almost everything people eat without paying attention? I almost starved in that period!) (and gasoline to and from the office, 32 miles per round trip)