I have this gerbil, Mige, and she is really fat. I got her from a pet store where they fed their gerbils those brown nuggets things, and I guess she was overwhelmed by my mix of food so I'm guessing she gores herself. Her two cagemates Ville, sister, and Vanilla, another pet shop rescue aren't fat at all so I'm afraid to give them less food. I've already taken out all of the sunflower and pumpkin seeds. Mige gets a lot of excersise from running around on my bed everyday. What can I do to get her to loose weight?