A murmuration of migrating starlings is seen across the sky in southern Israel December 31, 2015. (Photo by Amir Cohen/Reuters)

A flock of starlings flies over Lake Leman on an autumn morning in the Lavaux near Grandvaux, Switzerland October 20, 2016. (Photo by Denis Balibouse/Reuters)

“A ball girl is an individual who retrieves balls for players or officials in a variety of sports including association football, American football, tennis, baseball and basketball”. – Wikipedia

Photo: A ball girl runs with 2 balls for Ivo Karlovic of Croatia against Fernando Verdasco of Spain in their second round match during the Mutua Madrilena Madrid Open tennis tournament at the Caja Magica on on May 11, 2010 in Madrid, Spain. (Photo by Clive Brunskill/Getty Images)

Members of the general public enjoy the “BEACH” at the National Building Museum August 25, 2015 in Washington, DC. The “BEACH” is an interactive architectural installation, with an “ocean” of nearly one million recyclable translucent plastic balls, that brings the experience of going to the beach indoor. (Photo by Alex Wong/Getty Images)

Debutantes Amira Rayner, 19 (L) and Eliza Lewis, 17 (R) prepare at Boughton Monchelsea Place ahead of the Queen Charlotte's Ball on September 9, 2017 in Maidstone, England. (Photo by Jack Taylor/Getty Images)

A debutante from a local academy looks at her mobile phone as she waits to take part in the Vienna Ball at the Kempinski Hotel, March 19, 2016, in Beijing. The ball, which is an event organized by the luxury Kempinski Hotel chain and the City of Vienna, brings together both Chinese and foreign members of the capital's elite class. Despite a slowing economy, private wealth has soared in China after decades of rapid growth. A record number of high net worth individuals and families has fuelled a market for luxury goods, services, and events catering to China's burgeoning elite class. (Photo by Kevin Frayer/Getty Images)

Ariana Grande performs at Z100's Jingle Ball in Manhattan, New York, U.S., December 9, 2016. (Photo by Andrew Kelly/Reuters)

Sumo wrestlers of Nishonoseki clan appeal to the winner of a training bout for the next opponent during a joint training session ahead of the May Grand Sumo Tournament in Tokyo May 2, 2015. (Photo by Toru Hanai/Reuters)