Yes! It is possible, for snails, in general, to cohabitate with insects. I am not totally sure about sun beatles though. I think that would depend on the their care requirements, and if they align with the snail's care requirements. Some "insects" that can cohabitate with snails include isopods, springtails, worms, and millipedes. However, little research has been done into keeping millipedes and worms with snails, although certain snail owners have kept these critters with snails and say it is safe, be VERY careful in doing so. I hope that helped you out some! Let me know if you have any other questions!