Burlington Mall on March 8 is holding its third annual Diaper Derby, a crawling race that it bills as “the biggest tiny tots competition of the year.” The event, sponsored by the federal Women, Infants, and Children program and baystateparent magazine, will take place from 10 a.m. to 1 p.m. in the mall’s Center Court. Participants must be under the age of 12 months and not yet walking. There will be 72 crawlers, with 12 heats of six racers each. The winner from each heat will compete for first, second, and third prize. The winners will be presented with trophies at an awards ceremony, and all racers will receive a goody bag. The event will also feature activities that include a “Mommy and Me Lounge” and prize giveaways. There is no cost to participate. Preregistration is encouraged. To sign up, stop by the Guest Services booth in the Center Court. Registration on the day of the event ends at 8:45 a.m.