Black rat snakes are very very common around here,black racers look very similar but they have smooth scales and corns (red rats) have a Y shaped marking that suns from the neck onto the head.I believe our black rats down here have interbred with corns since many of them have red markings in them and we used to have corns down here but last one found was in the 1990's.I think the Black genome swallowed them.