The jaw-dropping survival tactic is goes down on Sunday's episode of the Discovery Channel hit -- Sarah Barnett's instincts kick into gear while wading through croc-filled water for food, and suddenly opting to turn the tables on the blood-bloated suckers.

Sarah fearlessly peels several wriggling leeches from her leg, gathering just enough to keep her hunger at bay and feed her partner, Sam Strong, in their battle for survival in the unforgiving wilds of South Africa's Black Hills.

Of course, Sarah's not aiming for Michelin stars here, she's just focused on staying alive -- as you can see when she bravely chomps down on one of those suckers ... seared over their campfire.

Sarah very nonchalantly informs Sam about the extreme menu item, telling him blood burst into her mouth when she bit into the leech.

While she has zero gag reflex, poor Sam feels the squeeze just watching Sarah chow down ... and decides to give it a hard pass, despite being absolutely ravenous.

Hey, everyone has a limit, even on "Naked and Afraid."

These California natives won't just be battling leeches; they're also dodging man-eating crocodiles, prowling lions, and venomous snakes during their 21-day survival challenge.