It seems like it's too hot in his cage. The glass cages heat up extremely quickly. I don't know what wattage your bulb is but you might want to bring it down. Keep it about 85 degrees in his cage.. considering his age. I love that you're asking most of the same things I was just a few months ago. Haha. He is probably going to the bottom of his cage and scratching because it is too hot. The bottom of his cage should be low-mid 70's then 85-90 at his basking spot. Chams thermoregulate which means they will move higher or lower depending on what their temperature needs to be. If he is on the cooler side.. he will bask, if he is too hot.. he will move to the bottom to cool down. Also, if you see him holding his mouth open often, that is a sure sign it is too hot. It took some experimenting with bulbs to find the right wattage at first. Considering you have the same set-up I do, I would go with a 25 watt for now.