Caring for a Hamster

Please can someone tell me if hamsters can function happily in the pitch dark? Because I need to cover him at night with a bed sheet or something similar, otherwise my cat gets over excited and I cannot monitor what is happening at night. My hamster is very active at night, but I do not want to depress her by keeping the cloth over her cage. I do not want to make her vision inactive. She seems to be happier without the cage clothed. tks,

Thanks for your feedback. That is a cute image of a hamster climbing the tree!
Thanks, Carla

I have only had one hamster after having cats all my life and wanting a pet that was approved for my apartment. What I did not know before I got it was their life span is only 2-3 years and you don't know for sure how old they are if you get them at the pet store. I was in shock when my little guy died after having him only a year.

Also they are nocturnal so they sleep during the day and are noisy at night. Mine didn't really take to handling but your experience may differ. I think if you get them young you can train them to like to socialize more. Mine was a sneaky guy and could pick the latch on his cage quite easily. We found him climbing the Christmas tree.