Although we are not told what school the boys come from, we can presume that they had attended different schools because of the fact that, with the exception of the choir, the boys do not know each other before the events on the island. We can back this up as Piggy is initially given the job of "taking names", and because all of the boys feel the need to introduce themselves during the first meeting.
Lord of the Flies documents the progression of "innocent" boys into savagery.
On the Island
The smaller boys in 'Lord of the Flies' are known as "littluns." They are the younger boys who are not part of the older boys' group.
The boys are savages, so they don't control the flies. Also, the lord of the flies is far away from castle rock, so they don't have to deal with it.
lord of the flies
The boys home country is England.
England
omak
Jack and the choir boys.
They were found by the military.
The last group of boys to arrive at the first meeting in Lord of the Flies are a choir led by head boy Jack Merridew.
Simon and piggy