I've figured out why Java didn't want to leave his cage for a few days. He wasn't getting enough sleep! Last night, I covered more of his cage so he couldn't peek through but also had plenty of ventilation, and I switched the blue led light for a plug-in night light that I had used before but stopped to experiment. He only chattered for about two minutes in the middle of the night, but I didn't respond and he quieted down. This morning, he's chatty, excited about being let out, and interested in his food again. This is such a huge relief and a learning opportunity, so I know what I have to do at bedtime. Thank you all for getting me through this and offering great advice. I'm so thankful he's back to himself again.