change in hamster behavior

Question
Hello! First of all, I think this is an incredible website and really really appreciate your help!
I have a teddy bear male hamster who is about 1 year old and 2 months. When we first got him from the pet store, he loved running in the ball and would run all over the place, never stopping until I got him for bed. After about 7 months, he stopped running in his ball. He takes a few steps until he is in a dark corner of our house, the "poop corner" and just sits there until I get him. He won't run anymore! He is still very active in his wheel and in good health otherwise. He still loves to chew and run in his wheel, but won't run in his ball. Is this something to be concerned about? I don't keep him in his ball more than 30 minutes, all stairs and everything are blocked off, so I just can't figure it out. What is you take? Thanks!!!
~Erin

Answer
There is no telling why he won't use his ball. Maybe he got a scare while in it. As long as he seems fine in every other way I wouldn't worry too much about it.
Maybe try it again in a few months after whatever scared him has faded from his memory.