Slitting is when you take a small scissors and cut through the skin of the pink or mouse down the back, about 4-5 slits, total. For a snake that has regurged, or a snake that is moving up in prey size, I'll slit both sides, too. I cut one slit through the skull, up to the hopper size. I slit all mice for all snakes until they are on adult mice, at 200 grams.