I've heard of raccoons getting stuck in someone's cat door, so if the holes are considerably smaller than that, I doubt it. They're pretty limber critters, but it would have to be a hole big enough for them to get their shoulders, ribs and pelvis through.

I've also never heard of them burrowing for shelter, but I'm no expert on that subject. One thing you should do with your mesh after you've determined whether or not someone's set up house, is to set it up so the mesh is sunken into the ground 4-6 inches or so. That would discourage most burrowers. It's a practice I'm sure many people in the forums have used to protect their gardens from raiders.

I've never heard of raccoons burrowing either. Could you have a woodchuck with an odd taste in housing?

I Googled raccoons and burrowing and apparently they do. Whatever is under there is definitely nocturnal. The coon sits right where the holes are and this is the place where he crawls up onto the deck.A holly tree is right there with a bird feeder so I know he is in that place every night. Well,I'm not going to poison him or trap him and relocate him so guess I'll just have to outsmart whatever is under there.

Maybe he's trying to dig out another [food] animal?

We had some raccoon feces on the deck a couple years ago; raccoons have sinced moved away (after my husband stopped feeding them nuts at nite/and they raided the feeders, took down the suspended suet block). I didn't like the p**p piles they left in areas of the yard and didn't want our dog getting roundworm or catchin' distemper. That's interesting that coons will burrow. Didn't know that either.

Other candidates for smallish holes under the deck - skunk (but you'd have smelled it), wood rat (generally nocturnal), groundhog (not sucha small hole)... I think that raccoons typically take over other animals' burrows, rather than make their own, if they are in a burrow.

i have coons which burrow through the insulation. pull electrical wiring out of socket. and if the head fits the body will follow. i have a 4 by 6 inch cat door and they go in and out at will. and i mean big ones. they also chew through almost anything. raccoons are the most destructive animals to a house which i have ever seen. maybe termites are worst but you don't mind killing them.