Can’t remember documentary style Desert Apocalypse Movie

I remember seeing this movie about 10+ years ago, so it’s at least older than 2012. But basically it’s an apocalypse movie that was kind of documentary styled. It had a family of four, with a boy and a girl. At one point they are in the desert and are about to eat a snake they killed when one of the kids says they won’t eat it. The dad gets mad and says something along the lines of “do you want to die?” The kid starts crying and eventually eats the snake. I don’t remember much else but I really liked the movie and want to rewatch. Any and all help is appreciated!! Thank you