They don't see you as part of their group so it's okay to be rude, try to intimidate, etc. Anything they feel they can get away with. Next time say boo back or some other goofy thing, but say it with authority. Straight authority however gets their hackles up. Most kids like adults with a sense of humor. But they are like dogs and they want to know where their place is and what's your place. Are you above or below them... because you're not part of the group, they want to intimidate and put you below.

It reminds me of when my classroom window got broken and I asked my students - 5th graders - if any of them had done something similar, broken windows, grafitti, to someone they didn't know. Probably 10 hands went up. And this is a good part of town. But it's okay in their minds to hurt someone you don't know. They are not part of the group. And it doesn't occur to them that someone they don't know may have feelings.

Communities are fractured, people are now afraid to discipline other people's kids, so the kids feel like they can get away with more.

Not all kids are like this of course. There are a good number whose parents are raisng them to have respect for all others, not just the members of their group.

V.