They do. They rush forward fast and, if they hit you, repeatedly run back and forth over your character... effectively causing death if you're unlucky enough not to get a chance to move.

Just a thought - might be caused by the order of their behaviors - as in they don't recognize you have been hit, and still attempt to approach even though you are already in the process of being hit?
Maybe not, but that's what comes to mind if they are not supposed to do so.