You can entice him out at a set time each night if you get him out for a run. I used to get my hamster out every night at half 8 or 9pm and she was in a routine, she would get out for an hour, not just in a ball but for a run around every night and she would usually go back to bed and come out much later at night...I think thats standard for them. Dont push him though if he doesnt want to, try to respect his nest
This is my last night with my hamster, vets tomorrow
shes slowed down considerably....enjoy him...wish we could have them a little longer!