If you fly regularly, you have probably noticed the strange posture of the cabin crew. You may have noticed that one of them always keeps their arms crossed behind their back, while greeting passengers.
But what crew members do not tell you is that, there is a good reason for hiding their hands.
The real reason, is that the member of crew is hiding a clicker behind their back, counting the number of passengers as they board. On long-haul flights you may often see them moving through the cabin clicking away.
So, when you board your next flight keep an eye on the member of cabin crew's hands.