A Moveable Garden

What do you think this grey squirrel is digging for, and apparently finding? The squirrel is nosing down several inches to find whatever it is. It’s not an area where I have thrown bird seed or peanuts, though some could have migrated there, I suppose, in the wind or dropped by birds. It is where my most organised vegetable and flower garden was planted last year, possibly where some flower (zinnia, cosmos) seed heads could be lurking under the snow.

I’ll have to go check out the site later today. Any guesses?