A caution about covering the light with a blanket. I once covered one of my aquarium lights with a towel at night because I couldn't sleep with it on. When I woke up the towel caused the water temperature to raise so much that all my fish were dead, they boiled to death. Im not sure how much that would cause your terrariums ambient temperature to raise by, but Im guessing quite a bit. If it works for you then don't worry about what I say, but I just don't want to hear that your frog got cooked And if you never had a light before, you should notice that your frog will be much more active.