+1. They're nocturnal, a light throws off their cycles. If you want some sort of illumination, put a small 4 watt night in the room somewhere, that'll be like a full moon effect.They should definitely have a sense of night and day for so many reasons. They're far more active at night, hunting for food and such. I love feeding after the sun's been down a few hours!
I'm the same way. My family are night owls and we all stay up until almost 2 a.m, and will leave the light on if I don't turn it off. it drives me insane.Im flipping out if the lights are on and there is nobody in the room.
I really don't know what to think about the night and day thing. I mean I give mine that are out all the time night and day but some of my burrowers chill in their holes for weeks so I doubt they see much light. So who know's....