I've never had any issues like this. Not with any of my pacmans at least. I had a clutch of Mantids and one of the Ghost Mantis failed to shed right and got stuck in his skin. Isopods and springtails I guess sensed the struggle and tried to eat the Mantis alive. The Mantis ended up dying after the shed so I'm assuming the Isos and Springtails just knew it was the end or something. But again. This wasn't told to scare you further. This has never happened with any of my frogs. Even when a pacman was sick or dead.