Why Does This Gazelle Have A Hole In It’s Face That Eats Things??? – [Video]

OK, I need your help. The other day, I was watching some nature show, and it was featuring Gazelles. Then all of a sudden, I had to pause what I was watching. What did I just see? A gazelle turns his head to the side, and a strange alien hole underneath his eye starts munching on a twig thing. Wait, WHAT? What am I seeing? I've watched this about 50 times over the past 2 weeks, and can't figure out what's happening. It's not his eye, and it's not his nose or mouth. I've googled this a hundred times and can't find any answers. Do YOU have a clue what's happening? I was not aware that gazelles had an extra mouth, or, whatever this is. Or, is this not a normal characteristic of gazelles, and this one has been crossbred with an alien?