If it were me I would hire 2-3 Cocker Spaniels w/ night optics and send them in like a seal team 6 style of approach for your wayward guests.
Most likely there is a leader in that family of squirrels. A very rich and powerful squirrel who has lived off of your misery these past couple of months you can be sure.
Maybe get some stealth hanggliders pre-wired to explode upon landing your death squad of pooches. You don't know how many of your enemy you may take out with that giant ball of flame. Make it look like an accident and then leave everything behind.......SO THEY KNOW YOU WERE THERE and can tell all of the other squirrels that you live and that YOU ARE REAL and should be FEARED. You want it to say "MOVE OUT OR DIE."
You laugh, but Cocker-Spaniels are patient creatures. The sit ALOT and watch you and sleep, but they are always vigilant and prepared for any obscurities to raise their head. Don't be fooled by the jolly faces and doe eyes these animals posess. It is is all part of the suit. Good luck to you and soldier on. You can win this......btw: I know a guy who knows a guy who has a cousin in a NM prison who has a lead on a couple of these assassins if you ever get serious. CALL ME..........
I've got a prayer on my desk. It says, "Dear Lord, I pray that my place will never be with the cold, timid souls who do not compete yet criticize, for they never know or feel success or failure."
~ BoB Stoops