Mine deffinately are awake during the day and sleep at night, I'll costantly walk by the tank and throw in a couple freeze-dried krill for them to eat and they snatch them up right away! At night, their patterns fade so they look almost all tan with very dark markings on their fins, and my longnose will lay on the bottom, motionless. I don't know if it's because I almost constantly feed them snacks during the day which is why they are awake or if it's just natural for them, I think gars in the wild are more active during the day, but I haven't done the research for my self so I can't be 100 percent sure.