disruptive child

hi, so the hardest thing i have to deal with is disruptive boys. i coach under 9s. they are a good bunch of lads. but sometimes they spend alot of time messing around. i try to keep them active and doing drills or matches. but balls end up flying everywhere. the last thing i want to do is raise my voice. i do a sin bin for 2mins. is this a good idea? or is there something else i can try?