Its been going on for a while (many months) at drop-offs. But I'm starting to see it more often at pick-ups, perhaps b/c he is more likely to be engaged in play with others lately than he was before: my 3.5 yo son often lashes out (scratches, hits, yells) at his friends when I drop him off at his childcare center and when I pick him up. We try to tell the other kids that he needs some space in the morning before he is ready to play. (They do tend to come up to us and get in our faces.) He used to say "no, MY mommy"--like he didn't want to share me.
But the last few days he has been lashing out at his friends that he has been playing with nicely, when I ARRIVE. These are the kids that he usually plays with; that he talks about on the weekends. I think he is generally less hostile than the average boy. His teachers have repeatedly described him as "kind" and he has been known to approach virtual stranger children in distress to offer a hug of support.
I'd like to think that it is anger about something else that he is directing toward his friends. But I can't figure out what. It makes sense that he wouldn't want to share his mom, especially when she is just about to leave. But at the end of the day, do you think he is sad to have to say goodbye?! And expressing it as anger? Any other ideas? Do your kids do this?