Who were the littluns in Lord of the Flies?

In Lord of the Flies, the littluns
are the smaller boys on the island.  As stated in the above response, there does not
seem to be a definitive age at which the boys are considered either littluns or biguns. 
The littluns are characterized as the boys who need to be taken care of by the older
boys who assume positions of leadership on the island.  Most of the littluns are not
named; however, there are some who are prominent.  For example, Percival is one of the
named littluns--he is the smallest boy on the island and he is symbolic of the
irrational fear that the boys have of things coming to "get" them.  Percival is often
heard crying, and he sets the other littluns on edge.  Another prominent littlun is the
boy with the mulberry scar--although he remains unnamed, he is symbolic of the boys'
downfall because he goes missing early in the story.