I work night shift and keep my v4 on normal day hours. This means it is usually awake while I am asleep. I take care of it in the morning before I go to bed and the afternoon when I get up. Otherwise, if it is dying, it cries loudly enough that it always wakes me up, since I keep it near me. I would not be afraid to leave it unsuspened at night. It should sleep just fine, waking at 8 or 9 depending on its age.