The insect in questions sounds like a species of the dermestid beetle. This a carrion feeding insect & feeds on dead insect or other animal tissues. Basically it is an indication that you &/or the supplier needs to clean the dead cricket carcasses more often. As far as feeding the beetle larvae, I've heard conflicting information. Some people indicate that the hairs on the beetle larvae can irritate the digestive tracts of lizards & others believe that there is no problem feeding them to their lizards. I believe that the beetles are a lot safer to feed to lizards, than the larvae, but wouldn't recommend either as they may have pathogenic bacteria from the carrion that they feed upon.