A red squirrel found a reddish berry and hauled it away to eat. (But, I have been unable to determine what the species of berry it is. It seems that no reddish berries are yet in season here.)
The squirrel picks up the berry and examines it.
Deciding the berry is worth eating, the squirrel sets off with it in its mouth.
And a moment’s glance to see if anyone is watching before vanishing up a tree.
That looks like an oak gall to me caused by the eggs of tiny gall wasps laid in the tissue of an oak tree. Not normally eaten by squirrels but they are hoarders.
It could be an acorn that is missing its cap.
I like what Eurydice & Florence have suggested, for it looks like no berry I know!
Norma suggests hazelnut. On zooming in, that does appear to me to be the most likely.
Counting a private comment, there are roughly equal guesses for the output of the oak tree and the hazel tree.