It's totally normal especially for winter/spring months. That's breeding season. Weigh regularly, and offer weekly/biweekly. I've seen in my experience raising/breeding/keeping balls is that if you feed less meals but bigger meals you are setting yourself up for a fast. If you feed frequent smaller meals they may still fast but you'll have less of a chance of that happening. I only had 3 out of 14 male go off feed this year. Most ate right through breeding. I feed weanling rats weekly. To all my balls. Just because they can handle a big meal doesn't mean they have to eat a huge meal. Winter they slow down to biweekly or every third week on their own. But that's 1000x better than a 10 month fast. With cooling season they automatically will want smaller or less meals. But if you feed smaller and more frequently they will be less likely to stop altogether.