We're going on vacation, and my in-laws told me to cover my sink drain with a piece of paper and place a glass upside down over it. I didn't want to seem ignorant by asking, but I'm really curious. Does anyone know why?

The Two Disasters This Hack Prevents

By placing a piece of paper (or a small square of cardboard/plastic wrap) over the drain opening and sealing it tightly with a heavy, upside-down drinking glass, you are creating an artificial backup seal. This protects your home from two major vacation nightmares:

1. The Dreaded Sewer Gas Smell

Without a barrier, evaporating P-traps allow methane and sewer gases to seep into your home. There is nothing worse than opening your front door after a relaxing vacation only to be hit with a wave of a foul, rotten-egg odor that has been building up in an enclosed house for days.

2. Uninvited Pest Invasions

A dry drain line is an absolute paradise for creepy-crawlies. Drain flies, fruit flies, and sewer roaches are constantly looking for moisture and organic matter. When the water barrier disappears, they will happily crawl up the pipes and make themselves at home in your empty kitchen. The weight of the upside-down glass ensures they are completely trapped beneath the sink line.

How to Do It Right Before Your Next Trip

If you want to adopt this brilliant, zero-cost trick for your next getaway, the process takes less than thirty seconds.

Pro Tip: If you are going away for a prolonged period (like a month or more), pour a tablespoon of mineral oil or vegetable oil down the drain before covering it. The oil floats on top of the water trap, drastically slowing down the rate of evaporation!