I have a 22-month-old DS and I baby-sit a friend's 20-month-old DS during the week. Since they're so close in age, we've had to do some work with normal toddler behaviors (biting, pushing, taking toys, etc) in order to keep everyone safe & in some level of harmony.
My conundrum is this: what do I do/say when other kids do those things to them? The more they understand that those behaviors aren't okay, the more offended they get when others push/hit/take toys from them.
Usually, I don't step in when someone else's kid is doing something because I figure it's not my place. I mean, if it's truly a dangerous behavior, I'll try to re-direct if the parent isn't around or isn't addressing it, but other than that, I try to stay out of it. But at this age, it's not like they have great tools to handle these situations--either they can throw a tantrum, push/hit/take a toy back, or just get over it. It's not like they (or the other toddlers) have the language and social skills to talk through these situations.
So how much do you help your toddlers navigate social situations? Do you ever talk to other people's kids about dangerous or universally unacceptable behavior? (I'm assuming here that things like biting, hitting, and pushing are universally unacceptable!)