Have you ever noticed how, before flights, one of the attendants who welcome the passengers onboard always keeps her hands behind her back? If you are an attentive traveler, you must have given it a thought at least once. Why would they be doing that? Have they got anything to hide?
As it turns out, they don’t. This mystery has a simple explanation: flight attendants have to count passengers before takeoff. In order not to lose count they use clicker counters, such as the one pictured here:
This is why their hands are hidden, so as not to attract too much attention to the process. Sometimes flight attendants count passengers after they have been seated, and sometimes it's done twice: during boarding and after seating. So the next time you see a flight attendant walk down the aisle while you are waiting for takeoff, look at her hands – and you might notice the telltale click-click motions.