Weeeeelll ... hopefully all visiting "guest" will remember to;
Share everything.
Play fair.
Not hit people.
Put things back where they found them.
Clean up their own mess.
Don't take things that aren't there's.
Say "I'm sorry" if they've hurt someone.
Be aware of wonder around them. Remember the little seed in the Styrofoam cup: the roots go down and the plant goes up and nobody really knows how or why, but we are all like that