No, they do not. Although they can certainly chew on adventurers with their toothy maws.
Unless a particular Pit Fiend managed to get spawned on the Prime Material or otherwise get the Native subtype. Which is uncommon, to say the least, but cannot be completely dismissed. Anyway, there are other counters to the Pit Fiend theory, such as having a parent, huge mental stats, or the reason why exactly Xykon didn't already milk the MiTD's wish. Hmm, that's quite an apt metaphore for handling critters endowed with wish SLAs.
"And I'll forgo the usual devil's food cake joke."
Was that sarcasm? Or an honest attempt to avoid a bad pun? Either way, this rule lawyer does not care.