More constructively phrased: make them run around outside a bunch during the day, and don't let them use devices with screens after dark.
Works for adults, too (especially if you also reduce use of artificial lighting) though it can be a struggle to fit that into modern life—especially in the Winter, since kids don't do much running around at school these days and it's dark shortly after they get home.
As a parent, I can state that getting lots of exercise is very useful in persuading kids to go to sleep at a reasonable hour. It's not bad for the parents, either.
Works for adults, too (especially if you also reduce use of artificial lighting) though it can be a struggle to fit that into modern life—especially in the Winter, since kids don't do much running around at school these days and it's dark shortly after they get home.