I remember reading somewhere that small hive beetles can chew holes in the woodenware. Well, when I removed my hive top feeder, I found two drone cell diameter sized holes about 1/4 inch deep into the front face of the wood. My assumption was that this was caused by SHB, so I just bought a SHB trap. I have never seen any SHB larvae or fermented honey in combs. Are my assumptions likely correct?
The other thing that it could be is perhaps ants. I have seen several larger sized black ants around the outside of the hives. The bees though seem to do a good job of keeping them out of the hive because I have only seen them on the outside or around the edges of the hive top feeder.