Yeah, simple courtesy goes a very long way
This whole thread must be terribly off putting to many people.
I know I laid out clear ground rules for a meet up once ( in the most part because I was being firmly encouraged to do so by people who were thoroughly fed up with the same issues happening time after time, and thought this might ease things all round) and then being rather dismayed at the meet up when the very young son of one member admitted that he had been so put off that he nearly didn't come, and was surprised to find that I wasn't a really, really, strict schoolteacher
That said, at the same meet up one parent was so displeased that I stopped his toddler son from waving a lit stick around, poking it in and out of my cooking fire, that he took his family away from the group entirely
Cannae win, sometimes
At the end of the day, every company is different, and I think Squidders is right; respect for others, for the space/place and it's inhabitants, and yourself too, and it all works out.
cheers,
Toddy