I've heard that waterscorpions, centipedes and some tarantulas will eat them. However, many animals will reject Dermestid Beetles. Have you ever used them to feed other pets (inverts, fish, herps, birds or mammals)?
I'd be surprised if toads, carabid beetles (such as scarites, pasimachus or cicindela), large praying mantises and true spiders, or any kind of fish that eats snails and crustaceans would turn their nose up at a dermestid beetle. I imagine frogs might accept them too however the beetle's hard shells may cause problems for them.
