Lapwing by the Loch

Walking round the loch this morning I spied this lapwing, not in the area where they have been previously spotted. As I tried to get closer there was a sudden flurry of activity as dozens of these beautiful birds rose up from the grass and pebbles at the edge of the water ... up till that moment they had remained concealed. I could only watch as they wheeled and soared in the sky before coming to land again as far away from me as possible! I checked on Google and the collective noun for lapwings is 'Deceit' ..... I wonder who comes up with these words?