A spotless bathroom can still get cockroaches, because they aren’t always coming from dirt—sometimes they’re coming up through the plumbing. Roaches love warm, dark, damp spaces, and drains and pipes can act like a hidden “highway” from sewer lines into your home.

That’s why some people use a surprisingly simple hack: a balloon. Instead of trying to repel roaches with chemicals, the idea is to physically block the tiny gaps around a shower drain where insects can squeeze through. Even with a P-trap, low water levels or inconsistent use can still leave a path, and roaches can flatten their bodies to fit through very small openings.

The method is basically a DIY gasket. You remove the drain cover, cut a latex balloon to make a stretchy band, and fit it snugly around the underside/edge of the drain cover before reinstalling it. The latex fills small gaps so pests can’t slip past. Some versions let the balloon sit slightly into the pipe so it opens when water runs and collapses when the water stops.

It’s not a permanent “forget about it” fix, though. Bathrooms collect hair and soap residue, and if the balloon is too tight or misplaced it can slow drainage and create standing water—something roaches like. A quick weekly check helps. Used along with basic steps like reducing humidity, drying surfaces, and sealing gaps around pipes, it can be a cheap, non-toxic layer of protection that makes your bathroom less inviting.