RE: Beetle ?
When I had mine, a guy brought me a skull that had hung in his shed for a year,, and like the one you mentioned, it was completely dried out. I put it in with the beetles, with a couple other skull, and yes they did eat it,, but it took them a long time, it took them about a month to completely clean it off, but it looked just like the rest of the skulls when they were finished, I was surprised they cleaned it that well, but it didnt matter to them if it was dry.