Mosquitoes in the Bathroom: Where They Hide and How to Stop Them

Bathrooms are damp, dim and full of water, which makes them a favourite resting place for mosquitoes, and sometimes a breeding place too. If you find mosquitoes on bathroom walls or around the drain, it is worth finding out why.

This guide explains where they hide and how to stop them.

The short answer

Mosquitoes rest in bathrooms because the humid, shaded, quiet conditions suit them, and they may breed in standing water in buckets, mugs, drains, floor traps and leaks. Common hiding spots are behind the toilet, under the sink, on the ceiling and in dark corners. To stop them, remove or cover standing water, keep drains clean and covered, fix leaks, empty and scrub water storage containers regularly, use fine mesh on windows and vents, keep the room ventilated and dry, and treat persistent breeding sources. Check neighbouring rooms and shared drains too.

Where mosquitoes hide

• On walls and ceilings in dark corners.
• Behind the toilet and cistern.
• Under sinks and behind basins.
• Around buckets, mugs and storage containers.
• Near drains and floor traps.
• Behind curtains and in laundry baskets.

Where they can breed

1. Buckets and drums: Water that stands for days.
2. Floor drains and traps: Water that does not flow, or clogged drains.
3. Leaking pipes and dripping taps: Small pools.
4. Overflowing or uncovered cisterns.
5. Plant saucers and vases kept in the bathroom.

How to stop them

• Do not leave water standing: Empty, scrub and dry buckets and containers weekly, or cover them tightly.
• Clean drains: Clear hair and debris so water flows, and cover drains with a fine mesh or lid.
• Fix leaks: Repair dripping taps and pipes.
• Cover water storage: Keep lids tight on tanks and drums.
• Screen openings: Fit fine mesh on windows, ventilators and exhaust openings.
• Keep dry: Wipe wet floors and ventilate.
• Keep doors closed so mosquitoes do not move through the home.

Rarely used bathrooms

Guest bathrooms and unused toilets can hold stagnant water in traps and cisterns. Flush and run water regularly, and check floor drains.

Apartments and shared drains

Mosquitoes can come from shared shafts and drains. Report persistent problems to the society, and ask for inspection of shafts, sumps and common drains.

What not to do

• Do not use strong insecticide sprays in closed bathrooms without ventilation.
• Do not rely on fresheners and smells.

When to call a professional

If mosquitoes persist, a professional can find breeding sites in drains, sumps and shafts and treat them with larvicide where appropriate.

Frequently asked questions

Why are there mosquitoes in my bathroom?

Moisture, shade and water sources. Check for standing water and drains.

Are bathroom mosquitoes dangerous?

They can bite and may carry disease like other mosquitoes.

Do drains breed mosquitoes?

Clogged or stagnant ones can.

Is it safe to spray?

Use products as directed with ventilation, or call a professional.

This guide is part of IPest's complete resource on mosquito control. For identification help, prevention and treatment options, see our full mosquito control guide for Bangalore.