Lost in a barren and unforgiving part of Turkey, and forced to hide for days in a cave to get away from torrential rain and floods, a group of students turn to berries, grass and insects for sustenance. We speak to two of the students: Merije de Groot and David Mackie.

Plus, what happens when you’re surrounded by people, but still have nothing to eat? We hear from Amin Sheikh – who survived alone on the streets of Mumbai for three years from the age of five.

In the third of our Survival Stories programmes, the BBC's Emily Thomas is joined by Max Krasnow, an evolutionary psychologist from Harvard University, who explains how your tastebuds could save your life, and Dr Chris Fenn, a nutritionist and survival expert.

(Image: David Mackie, after being rescued in Turkey in January 2015. Credit: Anadolu Agency/ Getty Images)