This just happened today. I peeked in on my texas brown millipede and his color looks off..sort of dulled, brown gray and his legs seem paralyzed. He is trying to dig back into the soil w/no luck, so I just covered it myself. And his 'antennas' are just tucked onto his head. He was also curling and uncurling many times.

He has never acted this way before, so I'm assuming he is sick, yes?