find youself in the company of spies. Here is how to tell.

You will notice many people who fumble with their papers, who are missing their passports, or whose passports have expired or do not have the right visa. They have trouble with customs.

You will also see many people who have contraband (usually booze or jewelry) in their luggage. They have trouble with customs.

You will see people whose ticket are invalid. They have trouble with customs.

You will also see a few people whose papers, tickets, luggage, etc are all in perfect order and who breeze through customs. These are the spies.