Awww I'm so glad it worked!!!UPDATE: Worked like a charm! While laying in bed last night, I forgot I had a set of three decorative oval mirrors in storage outside in the shed. The smallest one fits easily along the short side of the brooder cage, but it was too dark to get it then. I woke up around 6am and got it just as it was getting light enough to see out there. And I had a little "quacking" cadbury bunny that was given to me after Easter, sitting in a box - of all the stuffed animals I could have right then!
And I haven't heard a thing since putting those two in his brooder this morning! He does still chirp like a normal curious chick, but being in another room I don't hear it. And it's a very far cry from the extremely loud, lonely chirping he was doing (and all chicks do when they are alone). So it solved the problem completely! He actually hasn't touched the bunny at all yet, but he is completely enthralled with the mirror chick!
Although it's so cute watching him trying to peck at the little imperfections on the other chick in the mirror, or peck at his toes to see what they are, and he only hits glass! Lol! But he does cuddle up against his new mirror-friend for naps!