It's no coincidence that the kids who act the shittiest in play areas are the ones whose parents just dump them there and go off to do their own thing or go sit where they can't see their kids.
Granted, I often feel like a bit of a mother hen hovering over my daughter as she plays, but it gives me the invaluable opportunity to do a number of things: Watch my little one play and explore her world, give her praise when she shares/takes turns/doesn't cry when some snot steals her toy, help her up when she gets knocked over by said snot, and be involved in her childhood as an active participant, as opposed to the "potted plant" approach of letting the kid grow in the corner of the house somewhere and never pay her any attention beyond nourishing it and making sure the cats haven't used her as a kitty litter again. Should she ever be rude to another kid, it's also a chance for me to help her do the right thing. The bad thing is, I get to see other people's kids act like complete dickheads and I never know quite how to react.
I freaking hate it when there is a height limit for a play area and you've got these enormous kids, usually hyperactive boys, who go tearing around the tiny place like jet powered steam rollers and give you a million heart attacks with their near misses to your own little one until finally they do run right smack into your little peanut and make her cry. I do the "looking around for the parent" thing, but quickly learn that the sign directing parents to not leave their children unattended is option for those parents with the IQ of a mongoose.
Today, I took said peanut to the museum and she was greatly looking forward to her favorite bit where she gets to play with the sand table in the toddler area. If that's not a genetic predisposition, I don't know what is. Anyway, we get to the table and most of the sand is gone. Usually some gets spilled on the floor, but this was ridiculous. I've had more sand in my ass crack on trips home from the beach than there was on the table. And then I figured it out. Two boys, who were either 7 years old or suffering from gigantism, had taken it upon themselves to pile as much of the sand into their wheelbarrow as possible. Fine. I scraped together a sad little pile of sand for my daughter to play with so she reached for a shovel. One of the boys swept in and grabbed it first. So she reached for another. He grabbed that too. I watched this go on for a few moments longer as he made it clear that anything she reached for was, in fact, something he was just about to play with and had intended to play with way before she thought of it herself. It broke my heart to be a witness to such sad patience from my little one who could tell what was going on, even at her young age, and to such asshole-ish behavior from the boys.
"Wait a minute, baby girl. The big boy is going to give you THAT BLUE SHOVEL RIGHT THERE and LET YOU TAKE SOME OF THE SAND to play with." I cheated really by using my teacher tone. It's sort of like using the Force, really. "These aren't the shovels you're looking for, so fucking MOVE ALONG you little shits."
Okay, so I didn't say the last part because the Star Wars reference would have totally been lost on the pair of them so why bother...? Needless to say, she got to play with her sand. And not only that, but she went over to a little baby boy who dropped a ball he was playing with and gave it back to him, got herself a ball, and then gave it to him as well when she'd finished playing with it.
That's my girl.