Something is in my garden and I don't know what...

Washington State, zone 7A.

I have a small garden I'm growing in our backyard, 99% containers with one raised bed for my squashes and zucchini. We're dealing with a pest we need help identifying.

It started with holes popping up in the grass out there. We figured mole or gopher, as we get a lot of them around here. We mixed the dirt with cayenne and filled in the holes and stomped them down which is how we usually deal with it without an issue.

That problem stopped, but three more holes appeared without the mounds of dirt. One going under the house, one in our raised bed (sadly we didn't include mole netting when we put it in, we were totally green newbs with gardening then), and one near the concrete patio. Something was also digging in our pots, wheelie beds, and in one particular spot of our raised bed, top down not ground up. Didn't seem interested in the plants, it would just shove any of the seedlings out of the way.

Looking at the holes and with all the flooding we had around here, I concluded it was rats. I mixed some soil with mint repellent, cayenne, and garlic powder and filled in the holes. I also added mint repellent between the squash rows of the raised beds and planted marigolds at each end. I also got several potted mint plants and situated them around the yard.

THAT stopped. No more holes. However, something is still digging in our pots. Here's what we know:

-Doesn't seem to be bothered by the mint or mint repellent: one of the pots it dug in was the mint we just bought, and it shoves the mint repellent out of the way just like the seedlings.

-Doesn't seem to want to actually eat our vegetables or their seeds; we suspect it's looking for grubs or worms.

-Can climb or jump into wheelie gardens and container pots. Seems especially interested in our container of carrots and turnips. Not so much our chinese cabbage, though it did dig in there today.

-Will dig/has dug in our various beans, our potato bags, potted roses, eggplant, tomatoes, and mint.

-Has not touched our potted blueberries (peat moss) OR our big spinning garden tower that has sage, chard, garlic, thyme, and chives in.

-Digs from the top down, holes ranging from the size of a circled thumb and forefinger, and the palm of my hand/roughly teacup sized.

-Only happens at night. Only happens in the backyard, not in the front where we also have roses and a flower bed, but no vegetables growing.

-Wooden slat fence, no holes dug beneath it. No new holes in the yard since we added the mint and mint-repellent.

We need to pinpoint the pest that keeps doing this so we can pinpoint it directly, BUT we need a safe, organic method we can use around food crops, and we would prefer not to trap or call an exterminator (though I will if everything else fails).

Can anyone help with suggestions it might be?