I've noticed for quite some time now that Tulla, one of my girls who is about a year and a half old, is drinking a lot more than usual. When I hear the drinking sound at the water bottle and glance over, it's usually her. Otherwise, her appetite and behaviour are fine. I searched to find info here about excessive thirst in rats and it said it could be diabetes, and that there is nothing to be done. Is there a diet she should be on, like limit sugars (banana, fruit)? Thanks!