I picked up a juvenile Azureus dart frog at an expo today. He explored his home for around 10 minutes, but for the rest of the day ( and night) he's been hiding in the top right corner of my tank. He climbed the background and is staying in a little gap between the background and the glass top/ lid. I see his head, but that's about it. He's not stuck, and he could easily get out if he wanted. What should I do? Should I just leave him there? Is this normal?