Most people focus on the obvious steps when preparing for a vacation: adjusting the thermostat, emptying the fridge, watering plants, and checking all the locks. But many overlook a small detail that often causes the stale, unpleasant smell many homes have after days or weeks of being empty — the sink. When no one is using the plumbing, the drain can become an unexpected source of odor and moisture.

Every sink contains a P-trap, the curved pipe under the basin that holds a small amount of water. This water forms a natural barrier that prevents sewer gases and insects from traveling up through the pipes. When a home is occupied, daily use keeps that barrier in place. However, when the house sits unused for several days, the water can slowly evaporate, leaving the drain open to odors and pests.

A simple, free trick can prevent this: place a paper towel over the drain and position an upside-down glass on top. The towel acts as a breathable shield, blocking rising smells and stopping insects from entering, while still allowing minimal airflow so condensation does not form. Unlike rubber stoppers, a glass won’t warp or accidentally loosen while you’re gone.

For added protection, clean the sink before leaving. Rinse with hot water, pour a little white vinegar down the drain to reduce residue, and dry the basin completely. Then place the paper towel and glass in position. This small habit takes only a moment but can make a noticeable difference when you return. Instead of coming home to a musty bathroom or a sour-smelling kitchen, your home will smell fresh — exactly as you left it. It’s a simple, zero-cost step with a big payoff.