All greyt advice! I cover all my cages, but as Judy says, my cages are so big that the sheet barely covers the top half. Talon who sleeps in my bedroom, not with the others, requires a nightlite or she will have night terrors... The others don't, but I am very vocal about bedtime, scrithes, time for bed, nite nites, see you in the morning, love you Rikki, Nilah, Talon.. They know what bedtime is and will get in their sleep spot before I cover them.