One teaches children to enter a museum or library with wonderment and a wish to learn, yet with a degree of reverence; it isn't a playground.
If your children act the goat, not only are they disturbing others, they clearly have not be told, nor understand, why they are there.
As a parent of more than a few kids of my own, I can say from my experience that even if you raise them all the same, some kids will understand and behave exactly the way I would hope—full of wonder and reverence—and others will act the goat, over and over. Some kids are different than others. Even in the same family. I can only imagine how much the difference might be from one family to another—even if all the parents make sure they have been told and understand why they are at those museums or libraries.
Also, I’ve been using the em-dash since the late 90s.
You can lead a horse to water, but you can't make them drink. Being told, understanding, and choosing to behave well are not perfectly correlated. They will choose their actions for themselves. Of course you don't allow them to continue acting that way and over the course of time try to raise responsible adults.