I didn't think they would hurt anything but I was unsure if they die due to the extreme moister in the tank. I have seen the occational stray worm crawling on the coconut hut so I know they are lasting several days, before they either get eaten or drownd. I was hoping they might help fatten up the frogs when feed occationally. I know they do wonders for my fish. The frigs seem to eat them OK. They don't stick to the tongue as well as the flies or crickets. I keep you all posted.