When I dust the flies I put the dust in a small container, dump flies in, mix, then let the flies crawl on my finger and then shake my finger above the tank to get them off. Sometimes some of the dust gets on my finger and a very small amount will fall into the tank. A few times the dust has landed on the frogs, they dont respond to it but I spray them with water to get it off.... Does this dust hurt them if it comes in contact with there skin?..... may be a silly question.