I had a pigeon loft with a brick apron upon which I set my sills, and "something" dug under the footing and ate all baby birds in the loft.
I placed a large rock in the hole thinking it could not possibly be moved "DUMB" and the second night the digger returned, this time it dug around the boulder and got all of the remaining eggs.
The third night I placed two havahart traps baited with chicken wings, outside my loft, and a leghold trap inside my loft, in case the digger returned to sup again.
About 2AM my brother told me there was activity at the loft, and I saw a skunk , foot in the leghold trap, digging in to try to hide.
Well, we had a shootout- I shot him, he shot me, and neither of us missed. Made for interesting conversation in the carpool the next morning.
I find that an apron made from chain link fencing salvaged or acquired on craigslist is a simple deterrrent to diggers, as they do not seem get it, that they have to back off from the coop wall to get by or under the chain link. It eventually sinks into the ground on its own, and can be mowed over easily. Zip ties connecting it to the bottom of your coop work for the open or wire part, and staples work to link the fencing to a wooden pen bottom if that's your arrangement.
