I usually don't cover my 4 year old DYH at night. Usually his area is really dark once the house goes to bed. I tried a couple of times to cover his big cage but when he moves around in there while I'm covering it makes me think he stresses out. Lately in the morning he's been way too loud to get me downstairs before I'm ready to come down. So now i'm thinking of covering him for the night and uncover him when I'm ready to come down which isn't that late, around 8am. how do i know he's not stressed when i cover him for the night?