I just Googled to see why snakes die on their backs and there was nothing.

There was, however, some other "interesting" questions people were asking.

"Will a snake grow its tail back?"
"Will a snake kill itself with its own venom?"
"How do old snakes die?"
"Will a spider bite kill a snake?"

and my favorite:

"Will a snake die after it bites?"

Welp, i got my laugh for the night, off to bed.