The Gross (but Smart!) Reason You Should Plug Your Drains Before a Trip

Before you take off on your summer trips, you’ll want to take care of one essential task: plug your drains! Bugs such as cockroaches can work their way up the plumbing in your sinks, tubs, and showers when you’re away, which is a very unpleasant welcome home. We asked experts for the best way to keep these pests out while you’re away.

Why Are Roaches Attracted to Drains?

For three main reasons: moisture, food debris, and shelter, explains Jim Frederick, PhD, a board-certified entomologist and the Senior Vice President of Public Affairs at the National Pest Management Association (NPMA).  “Your home’s plumbing is like a protected highway for cockroaches since they can avoid predators and travel without much difficulty,” Frederick says. And drains are a source of gunk that these creepy critters eat, such as food particles, grease and soap scum, says Trent Frazer, lead entomologist and senior director of quality assurance at Aptive, a pest control company. “Furthermore, roaches’ remarkable adaptability allows them to navigate wet environments and even survive submerged conditions, making it easy for them to climb up through drains,” Frazer says. 

With daily use, water stays in the P-trap, the curved section of the pipe underneath your sink, Frederick explains. That water offers a layer of protection. When you’re away, the liquid can dry out and leave your home vulnerable to pests, among other things. “Without the water barrier, intended to prevent sewer gases and pests from entering your home, cockroaches have a clear path to move from the sewer into your living space,” Frederick says. 

Even if you’re not away, it’s a good idea to run water in guest bathrooms or drains you may use infrequently, Frazer says. “At Aptive, we recommend periodically running water in all sinks, tubs, and floor drains, even if they’re not used regularly, to keep the traps filled and help block pest entry,” he says. “And if you’re noticing roaches emerging from sinks, tubs, or floor drains, it’s a sign that conditions are favorable for an infestation and may also indicate a deeper issue within the plumbing or nearby sewer lines.”

How to Keep Bugs Out

You may have seen videos of people covering their sinks with vases or bowls on TikTok. But that likely won’t create as tight of a seal as you need. “Cockroaches need only 1/16 of an inch of a gap to squeeze through,” Frederick says. The best way to keep pests out is by running the water in each drain before you leave. “The water seal in the P-trap can help prevent cockroaches and sewer gases from coming up,” Frederick says. Then, you could use a tight-fitting drain plug to create an airtight seal that pests can’t penetrate, he says. “The plug helps maintain the water seal in your P-trap by preventing evaporation, providing a second layer of protection,” Frederick explains. 

It’s a good idea to take out the trash, wipe down surfaces, and make sure any food is stored in sealed containers before leaving, Frazer advises. If you have an ongoing battle with bugs, consider working with a professional pest control provider, he advises.