Where does Ralph hide from the tribe and why doesn’t it work?

Ralph crawls away to a thicket where he can safely sleep. When he awakes in the morning, he can hear Jack torturing one of the twins and talking to Roger outside the thicket where he hides. They are trying to find out where Ralph is hiding. Several other boys are rolling rocks down the mountain, trying to break into the thicket. More boys are trying to climb in.