Opportunists, that's exactly what they are. They find a niche and fill it. They will take advantage. Efforts to correct the problem continue to be futile. Unless you accept them, the only thing that will be accomplished is the loss of a lot of money, stress, and ulcers.
Got trees? If yes you likely have a tree rat problem according to the lawn detective. If you ever take notice when you see a squirrel, there are always trees nearby. Trees provide a squirrel protection, shelter, and the squirrel super-highway.
These little critters dig up bulbs in the landscape and find our garage an opportunity for dry housing. A birdfeeder often provides them a chance for a free and easy meal. A chimney is often seen as a place to raise their offspring in warmth and security. A garden shed is an easy place to hide, but tease and torture the 160 pound Leonberger to the point of craziness.
Even though they were here long before us, there is a humane way to eradicate the squirrels. Create a distraction by hanging corn cobs from tree branches in a location away from the most sensitive areas of the lawn. A cob on either end of a 4 foot length of cord easily hangs itself on a tree limb when tossed up. With the dangling kernels being so difficult to reach, the squirrels have little energy left to go out to the other areas of the yard and leave the lawn alone. Their awkward antics are funny enough that the stripped grass in lawn almost becomes a secondary issue. While it is difficult to see the little holes in the yard, you have to think of it as not having to spend the money to have the yard aerated.
As Benjamin Franklin said, “In this world nothing can be said to be certain, except death and taxes …”
I would like to add “squirrels” since we can't control Mother Nature. She's a powerful force too.