Sorry, I wasn't really clear enough on what I am seeing. I don't have wax moth caterpillars themselves on the BB insert, just evidence that they are up in the hive (feces, bits of comb, bits of silk, etc.). The cluster in this hive is at least partially in the top box (I'm overwintering in 2 mediums), and I suspect that the waxworms are hanging out in the bottom box under/away from the cluster.