My first year with quite a lot of tomatoes outdoors, some got very little attention outside the main garden area and after awhile I noticed a squirrel-sized hole under a tree root near by.... and yes it took awhile to figure out that fruit were disappearing quietly one by one ("Why are they so late to ripen any?").
Also the first year I had really a lot of green fruit not worth my picking (started too late) and ended up trashing a heap of tomatoes in the special tomato plant compost pile... which developed an interesting burrow shaped hole in the top. So I poured water down it, deliberately, while stacking up the next layer. Now from my window I can see two burrow holes on either end of one side...Looking like a real work of engineering.
And ravens or crows have been perching up above hooting and hollering like they are very displeased.
Been worrying that it could be a rat, mostly because our little red squirrels are normally so noisy, especially if they see food, they can't resist squawking about it.
On the other hand, squirrels and indignant birds are proper hand in hand. They detest the tree rat, seriously.
I went and googled the red squirrel and they do burrow in the ground for winter shelter (and cache of food). Maybe they're only quiet when they're hiding stuff...
I guess I'll find out when the snow falls.... squirrels don't drag their tails in the snow.