Squirrel are interesting. They see me digging around and I think they assume I am burying something delicious. I have lost many young plants to squirrel damage. I bear them no malice, they are just being good squirrels. "Fucking squirrels!" is as far as my anger goes.
I have learned that the larger the pot, and more mature the plant, the less interest they show. They played hell with my seedlings in 1-gallon containers, but largely leave the 3-gallon containers in peace.
Even in the rare cases where they try to disturb the larger plants, the most damage done is a small squirrel hole in the large container. I can't recall any significant squirrel damage in relation to my larger plants.