Seriously, they're from a black rat snake. We cut down am old hollow oak that was about 48" dbh. Inside were several old nests of hatched out snakes. At ground level was a nest with good eggs in it. I hauled them to the neighbor and he stuck them in an old rotten tree he had, his pet rat snake disappeared a couple of months ago. They hatched a couple of days ago. About a dozen 6" rat snakes.