Actually he falls asleep very frequently almost everyday and our boss have never concerned or been mad about him. There was only one time that he snored quite loud and our boss patted him so he woke up. But since then he still falls asleep frequently and have not shown any signs to improve. Honestly I've been feeling strange about my boss's tolerating such a person, but I'm still not sure if I should keep pretending not noticing him sleeping, or I should tell him that sleeping at work is really not proper?