They used to dig up small plants I had planted all the time. I had to start surrounding new plants with rocks, it was crazy. Once I tried to grow popcorn in my backyard. The squirrels went berzerk. I tried to drench the entire plant in hot pepper spray but a squirrel dug up the bottom, chewed it off there, and ran around the yard dragging it in the grass to get the pepper spray off!
All the dumb ones are killed by cars and we are breeding super squirrels!
I’d be tempted to check tegulations if a neighbor is “feeding wildlife” in a residential neighborhood. Maybe anonymously report.
(In my area, they aren’t worried about disease, but the right sort of coexistence.)
One time when I was hanging out at the Boston Common, one squirrel acted like an overeager cat who hasn’t seen his/her owner in weeks. Came right up and went through my short sleeve and through my t-shirt.
Funny part was I actually felt it was a sign the squirrel was extremely friendly and was giving me a welcoming gesture. 
One example of some smart squirrels in action I observed was on another occasion in the Boston common. Two squirrels happened upon an opened drink which was mostly full. One hopped up to knock it over so his/her partner could enjoy the drink with gusto.
In contrast, one time while visiting a HS friend at her Harvard dorm(Winthrop House), one really hefty squirrel attempted to leap into her room while we watched. Unfortunately, the squirrel miscalculated…probably forgetting to take his/her heftiness into account and ended up crashing softly into a dumpster full of freshly raked leaves below.
Hefty squirrel didn’t seem seriously hurt, but it was clear s/he was seriously peeved through the loud angry chatter in a manner not unlike Yosemite Sam or Wile E. Coyote after they end up being foiled by Bugs Bunny/Roadrunner or when they end up being seriously injured by their own deviously set traps. The angry chatter from hefty squirrel only added to our amusement.
I think you should all Google “Mepps fishing lures squirrel tails”.
I always enjoyed watching the gray squirrels in our yard. Several years ago smaller red squirrels moved in. They are very aggressive and I don’t like them; they raid the gray squirrels’ nests and I caught one red squirrel running with a baby gray squirrel in its mouth. Apparently in Ireland and the UK they have the opposite problem - native red squirrels are being pushed out by gray squirrels. They can have my red squirrels anytime!
We have some black squirrels in the neighborhood – they are Canadian! The story goes that they were brought to the National Zoo in the early 1900s from Canada, and some escaped. They are not plentiful, but they are very nice-looking and not as aggressive as the gray squirrels that own our oak trees. The gray squirrels tear out all of my container plants, too. We once had a gray squirrel fall down a drainage spout – OMG, the racket! Had to take the downspout apart, and I though the little bugger was going to attack me when I got him free. Ingrate.
When S2 was little, his preschool class used to sing the Gray Squirrel song. S2, who was all of three, sang, “Gway squill, gway sqwill, swiss your bussy taewl.” Precious! <3