Upon closer inspection, it turns out that one of the snakes was dead. :-( Judging by the fact that there were two of them when I first came across them, I'm going to say that this was probably a mating pair. This is a little bit of anthropomorphizing by me, I know, but you had to see them laying there. It's almost as though one of them was paying its last respects. :-( Really touching, believe me.
Looking at this one though, it's hard to determine the cause of death. Quite big, the pair of them, this one being at least 3-4 feet long. And they're rat snakes, so they're harmless to human beings. Still, no point trying to intrude upon their peace for no reason other than the fact that they're harmless. A bittersweet moment to end the day. :-(