From left, Mallory Doody, 5, Natalie Cambre, 3, Madison Doody, 7, and Anna Cambre, 6, get ready to compete in a sack race. The children were participants in Nickelodeon's Worldwide Day of Play celebration at Stennis Space Center (SSC) on Oct. 1. The Worldwide Day of Play is sponsored annually by Nickelodeon television network to encourage children to be physically active.