Daily drinking. If a person feels a need to drink daily, that is a signal that there is a problem. The cage questioneer can also help. Do they feel a need to cut down on their drinking? Are they annoyed when you say they drink too much? Do they ever feel guilty about their drinking? Have they used an eye opener drink in the morning? Answering yes to one or more of these may indicate a problem.
The way he smell. And the way he behave, how much he drinks and how often if u need additional information let me know.