I watched it happen. They started twitching after about ten minutes and then convulsed for the rest of the time. I still have them in formalin. P-a-m has worked for me too, but this new stuff is totally harmless and kills the little bastards dead. I've talked with two company reps and they're even going to get FDA approval for treating lice and crabs on people like John E. who need help in those areas.