Heather and Jack are correct.

They can sense the change and will decrease and increase activity and food intake with the changing seasons. Always check on the frog if it has remained burrowed for a couple weeks. Most will increase food intake in spring and summer, but decrease at the end of summer to the start of fall, then increase again between fall and winter in which winter they will once again decrease activity and food. This doean't happen to all, but the majority of frogs will go through this phase.

Keep everything normal and all should be fine.