For the last ten years I have had a healthy population of yard birds and squirrels around the house. I run multiple feeders and enjoy watching them. I have even created obstacle courses for the squirrels to watch how they learn and adapt. This summer I noticed the squirrels were exhibiting wasting and the appearance of large hairless growths all over their bodies. At first I thought it was due to warbles(wolves), but the lesions did not have the usual hole in the middle. I looked up the condition and learned it could be Squirrel Pox. The recommendation was to withdraw food so they would not congregate. I did so, but apparently too late. Well, now there are no squirrels at my feeders, save one yearling. I guess I'm going to have to start over again.

Might also be mange.

Yep, + mange is easily contracted by association + highly contagious. However look at the bright side, winter is coming on + perhaps the cold will kill the virus; I don't know. I DO know that you're not going to hold down a squirrel,( even if you could catch him )+ douse him with crank case oil. If anyone in the SPCA saw you doing that, you would be in trouble! Honestly, I know what you mean; they are fun to watch as they figure out all your ways to keep then from the bird seed. I build a lot of feeders from my metal cutouts + do some bird/ squirrel feeders for Christmas gifts. Since they are made from galv. sheet metal, they last forever. Even did a few out of Copper. In the last couple of years I have taken several to the local nursing home for the elderly that have window access. They like watching.