Probably not the best idea... This 19-year-old, Katarina Zarutskie, recently took a swim in shark-infested waters in order to get a good photo for her Instagram profile... what what happened next was probably something we all saw coming.
As Zarutskie recalled: "I leaned back, and then that shark he came and he bit down on my arm and pulled me under."
She managed to pry her arm from the shark's grip, and get out of the water as fast as she could! She's ok and her arm is still with her but it could have been much worse!