It does not take a friend to blend into a group within few hours, but a friend's friend too. Several trips showed group dividing is an essential process. Not something on purpose, but it happens automatically. However, these smaller groups out of the bigger one do not have specific members as they change from time to time. Might last for hours or days. It probably takes a small incident to have such division to occur, or even, a several hours away from the original 'group members'. Preference during specific time too may influence the people in group. Kind a funny, but true.
