Before heading off on vacation, most people remember to check the doors, windows, appliances, and valuables, but one small area is often overlooked: the sink. If a home remains empty for several days, the water inside the plumbing trap beneath a sink can gradually evaporate, particularly in warm weather. That water normally helps block sewer gases, so when the trap dries out, unpleasant smells can move through the pipes and into the house. An unused drain may also become an inviting route for small insects searching for moisture.

Fortunately, preventing these problems is fairly simple. Run some water through the sink shortly before you leave so the trap contains fresh water. For an unused drain, you can also add a temporary cover to create another barrier. An upside-down glass can work well, while placing a small piece of paper nearby can remind you to remove it when you return. This is only an extra precaution, however, and should not replace regular plumbing care and maintenance.

If you’re going away for an extended period, remember that other drains can have the same issue. Bathroom sinks, showers, bathtubs, and floor drains may also contain traps that can dry out when they are left unused. Running water through them before your departure can help maintain the water barrier and reduce unwanted odors. It’s also a good idea to leave the sink and surrounding area clean and dry so there is less moisture available for pests.

There’s nothing mysterious about this simple trick—it’s just a small piece of home maintenance that is easy to forget. Locking the doors and switching off the lights are important steps, but your plumbing deserves a little attention too. Taking a few minutes to refresh unused drains and add temporary barriers can help prevent unpleasant surprises. Sometimes, the smallest preparations make the biggest difference when you return home.