They won’t feed from the tongs, I have tried & tried! I’ve also tried putting them in a separate plastic container, without any substrate, but that just stresses them out and all they do is pee all over. However, I am going to keep trying that, letting them in there a little longer each time to hopefully get them acclimated, especially when feeding worms. As you said, the worms get covered with substrate and I rinse them off as well but they squirm away to quickly back into the substrate. If I can get them acclimated to a separate enclosure, I could rest easy feeding them the rolies and the worms!