Question: I went to a new exhibition at a science museum while visiting my family over Thanksgiving weekend. There were interactive elements that were clearly aimed at children, and some were very popular — my daughter and I waited in line for more than 30 minutes so she could try one.

What really bothered me is that there were plenty of adults in line to do the activity themselves, who weren’t even with children. I estimated that my daughter had to wait five to 10 minutes longer because of this. It did look like fun, but when it’s crowded, shouldn’t adults act like adults and let the kids go instead?

Answer: There is a difference between an interactive activity aimed at kids and one restricted to, say, kids younger than 12. Unless the museum posts age restrictions, the adults have just as much right to participate as the kids do. That said, I wouldn’t have gotten in line myself either if there were little kids waiting. It would just feel selfish. If anything, I’d ask a museum employee when the line is shortest and plan to come back then.

Q: I was once stuck in the Transportation Security Administration line behind someone who had purchased a souvenir snow globe for each of her six grandchildren. It did not end well. So, while I already know the answer, I’m asking this question as a public service: Can I bring a snow globe on a plane?

A: Actually, you can, if it holds less than 3.4 ounces of fluid and can fit in the single quart-size zip-top bag of liquids and toiletries that you get to bring on the plane. This is new. TSA officials used to require you to check all snow globes (and even partially evacuated an airport in 2010 because they found a battery-operated snow globe in someone’s carry-on), but they recently relaxed the rules.

Email travel etiquette questions to Lesley Carlin at deartripadvisor@tripadvisor.com.