If I want to bring a packet of wet wipes with me on a plane, do I need to put them into the one-quart ziploc bag with all my other 3 ounce liquid containers? The TSA 3-1-1 Liquids Rule page doesn't mention wet wipes.
The other answers are correct, but they rely on the assumption that wet wipes are not liquid, gel, aerosol, cream, or paste, without any evidence that the TSA would accept that. As you correctly pointed out in a comment, wet wipes contain liquid.
How can we check whether the liquid contained in wet wipes causes them to fall under the 3-1-1 rule? Try the Prohibited Items page of the TSA web site:
Here, there is a box with the text "When I Fly, Can I Bring My...?" If you type "wet wipes" into the box, and click the "Go" button, you will get a pop-up window informing you that
You may transport this item in carry-on baggage or in checked baggage. For items you wish to carry-on, you should check with the airline to ensure that the item will fit in the overhead bin or underneath the seat of the airplane.
Thankfully wet wipes are not yet subject to the 3-1-1 rule. The rule applies to:
Liquids, gels, aerosols, creams and pastes
Wet wipes don't fit in any of these categories.
I always travel with wet wipes in my carry-on and I have always been allowed on the plane with them.
Nevertheless, what happened twice in the last week (May 2016), as I was flying domestically within Schengen, was that my packet of wet wipes was mistaken for a water bottle by the officer behind the X-ray scanner. My bag was therefore hand checked by another officer who let me go without problems and with the wipes. This is to say that recently security checks might have been tightened and, if travelling with wet wipes in your carry-on, your luggage could be subject to a manual check by airport security. This happened at Luxembourg airport and Rome Fiumicino.
I routinely travel with pre-moistened wipes of various kinds in my carry-on bags. Not only does the TSA not consider them a liquid, but neither do U.K. security (e.g., at LHR), which is far stricter than the TSA. While wipes contain liquid, they are not themselves liquid. Put more simply, there's no visible liquid when examining a moistened wipe.
I would assume so. Since baby wipes are allowed, according to the TSA website, I do not see the difference between baby wipes and wet wipes.