Old mama cat worked for me, she caught 3, the ones she didn’t catch left on their own I guess.
So, we had squirrels one year. Our eves had a vent along the whole length and the house was older. the previous owner hadn’t taken very good care of it (to feed her dog, she filled a lower drawer in the kitchen with dog food, and when it was time to eat, she opened the drawer and let them go to town–needless to say, we had mice problems as well). Well part of the vent broke open and the squirrel got in that way. It was over our bed.
So, we call animal control, and the told us to make sure the squirrel was out, then stuff mothballs in, then steel wool. The steel wool would act as a barricade long enough for the smell of the moth balls to drive it away. So we did this.
Then next day I get home and my wife say’s “hurry, you have to see this!” I go to the hole and I see the squirrel had pulled out about 10 inches of steel wool to make a “rope” coming out of the hole, was holding onto that with his back legs, and using his front to throw the mothballs to the ground.
That was it. I didn’t care how ugly it looked, I got chicken wire and wire up the hole. He punched a new hole in the vent (no it wasn’t already there, I checked when I put up the wire) just beyond the chicken wire. OK, my neighbors were going to hate me…I chicken wired the whole eve. It only pissed him off more. He tried to chew his way through the wood part of the eve. Did a pretty good job of it too, just couldn’t get through. I waved the white flag and paid a professional to trap it.
After it was gone, My wife and I thought that maybe it was a female and had babies–that’s why it was so adamant. So we went up in the attic to check. No babies, but we had just blown insulation in the winter before. From the hole he had cleared a path that led to two circular areas. One was empty, we thought that was probably where it slept, and the other had a cache of nuts. He’d built himself a little apartment in our attic and we evicted him. No wonder he wasn’t happy.
Honestly you should probably just buy a new house. The little bastards already have the high ground and are probably more clever than you, so you’re just fighting a losing battle at this point.
Have you asked them nicely to take up a new residence?