The first time I ever went deer hunting was in 1964. A neighbor had told my father that some deer had been seen in a woods that joined our farm, so I went there, Didn't see a deer, but saw more squirrels in that place than I'd ever seen before. They were every where I looked, I'm guessing I saw at least a hundred. I went back the next afternoon with my shotgun, deciding that squirrel hunting would be more fruitful than deer hunting, and never saw a squirrel. I happened to mention it to an older fellow in the community and he said that what I'd seen was a squirrel migration. I didn't really believe him at the time, but I have seen it again, so it does happen.
I bow hunted a place one fall that had a bunch of squirrels, and I packed a slingshot with me and would shoot at them with it. Never hit one, but did manage to scare a few.
Over the years I have witnessed squirrel migrations like you described several times. One day the squirrels are so thick it is almost kinda creepy. A guy could sit and shoot a limit in 30 minutes with a handgun and see dozens of squirrels in any direction at any time. A week later they are gone. Once I was fall smallmouth fishing and squirrels were swimming the river in large groups. All going the same direction. Fish a long pool and see a hundred squirrels swim across to the bank on the other side. We would motor to the next pool and see another swimming mat of dozens of squirrels crossing. The next pool would be the same. It was crazy.
