N.J. man allegedly killed squirrels with BB gun, hung them on fence

[haele]

117. Crows are scary-smart, have a long memory and studies show they understand concepts

For crows, something like that might work over a long term as they communicate. I've heard of farming communities that did that sort of thing - killing as many crows as they could and hanging the bodies up where the other crows could see just once and they haven't had crows in their area for decades afterwards. The crows decided that township and the area around it were just too dangerous and "the word got out". Even migratory corvids - magpies and jays - avoided those areas.
For squirrels, it might work until the bodies are no longer there (then again, the squirrels may just ignore the show of bodies as the concept of "hey, that might happen to me" doesn't apply unless they actually see the killing and the bodies put on the fence.), so he'll have to keep doing that.

Fix the hole and otherwise squirrel-proof as much as you can. That's the only way to discourage them.

Haele