Most people double-check the thermostat, lock the doors, and empty the fridge before vacation, but few think about the silent troublemaker waiting in the bathroom or kitchen sink. When a house sits empty for days, the water inside the P-trap slowly evaporates, leaving a direct pathway for sewer gases, mildew, and even insects to creep into your home. That “stale” smell so many people notice after a trip isn’t mysterious at all—it’s the result of an unprotected drain quietly pulling unpleasant air upward while you’re away.
There’s a simple, zero-cost hack that homeowners and professional cleaners swear by: place a paper towel over the drain and cover it with an upside-down drinking glass. It seems almost too easy, but it works because the towel acts as a breathable barrier while the glass prevents insects, odors, and rising humidity from escaping into the room. Unlike rubber stoppers, which warp or loosen over time, a glass won’t shift, react to moisture, or trap unnecessary condensation beneath it.
