Kudos to these kids for lending a hand to the more helpless creatures of this earth, but geez this has 'bad idea' written all over it. Blunt knife. Bitey snake. Not to mention the weirdness that happens around 3:30. Stick around for that, if you haven't puked of nerves already.
The kids may not have been right in believing the snake was "rewarding" them for their valiant efforts. According to the internet, garter snakes regurgitate their fod when stressed. Cool. I just did the same.