Thanks to the help from all you lovely folks on the frog forum I've come to decide that the most likely reason my frog is having problems is the temperature of his enclosure. I live in Maine and it's October. It's not warm. He does have a heating pad attached to the side of his tank, and I have thrown a rag and an insulated jacket over two thirds of the cage to retain heat, but it remains in the 65-75 range. What's the best way to raise to temperature of the tank? Another heating pad? Possibly a pad designed for a larger tank? A bulb? Any of these things in conjunction?