Every team has one or more, a fidget kid. It is the the team member who is always playing with the mission pieces, hair or just can’t keep still. It becomes more apparent in the judging room where it is a big distraction. I once had a youth start playing with mission pieces during technical judging.
You have two options, fight or embrace the fidget. I tried fighting, it is useless. To embrace the fidget, put something in the youth hands. We call this a fidget stick. For fidget sticks, I like to use Lego shock absorbers. They are entertaining and small enough they don’t cause a distraction. Fidget sticks are a great tool to use. You can order them on ebay for about $2 each.