"Mommy Cliques"

I have been thinking about this thing that has been going on in our neighborhood. Thing is not the correct word to use, it's more of an issue than anything. What is this need for mother's to treat other people (not in their little cliques) and children as if they don't belong? My biggest concern is my daughter. She began in this neighborhood having friends, playing everyday and being happy to feel wanted and accepted. Because we were new to this area we get treated as if we're not good enough to even talk to in mornings at the bus. Do people even concider the children in these situations? Even if these cliques don't accept the mother , don't treat children as if they are from the wrong tracks, so to speak. I've been thinking about this for quite a while and I was watching the news this morning and light was shown on this subject.
You'd think after high school people like that would have grown up! Well, that would never happen,lol. It's a scary thing for the mothers and their children to move into a neighborhood when there are people that have been there for a long time and no one else is good enough to be included. How many people have felt this way or have gone through this as a parent?