I spend most of my summers diving in wisconsin, and have never even seen a bowfin, let alone a snakehead. But if you caught one I would make the drive to buy one from you.
Could be lots of things at three inches: darters, bowfins etc... Did you see them in the water or out of it. I'd highly doubt that it would be snakehead, but you never know. I just always tend to go toward the probable before the unlikely.
The Federal study that is keeping track of the Northern Snakehead has had positive id of them in Lake Michigan, as well as small ponds in New England, so I definately think that their liklihood in Wisconsin is HIGHLY POSSIBLE, considering their residency in the Great Lakes. Their Distribution Map is updated daily. You can check it out here.
