Well...
Sometimes a good defense is a good offense.
Find solidarity with one, two, three or four other moms who find this a problem and just go over and start talking to the boys, asking them nosy questions, ask them where their parents are, ask them to go play with other boys. but go one one one or four on one, or four on four, whatever. The attention they get from the moms will scare the bejeezus out of them and they will NEVER COME BACK!!!!!!!!!!!!!!!!!!!!
Sometimes a good defense is a good offense.
Find solidarity with one, two, three or four other moms who find this a problem and just go over and start talking to the boys, asking them nosy questions, ask them where their parents are, ask them to go play with other boys. but go one one one or four on one, or four on four, whatever. The attention they get from the moms will scare the bejeezus out of them and they will NEVER COME BACK!!!!!!!!!!!!!!!!!!!!