No. They normally don't even take food into the nests to eat.
If you look around where squirrels are there are places where they take food to eat it.
They leave large piles of the shells or the cones, all taken apart.
Squirrel stashes are usually in holes, hidden under something or distributed in small caches around their territory. I wish they were easy to find but I have only ever found them by accident or by watching the squirrels making them.
Some squirrel stashes are strange. I saw a spruce tree once with all the branches between 12 and 16 feet above the ground with mushrooms on them. They got into one of my storage sheds once and filled a plastic pipe that was stored up in the rafters with maple keys. The squirrel had stripped the wing and husk off them so it looked like it was full of green peas. They do the same thing in hollow logs or holes in tree trunks.

Back to tinder sources?