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Staff setting rat bait in Seattle sewer system

The Seattle Sewer Baiting program aims to control rats in Seattle's sewer system and provides the following services:
  • Responds to citizen complaints about rats in their toilet.
  • Tracks neighborhoods that are impacted by sewer rat activity.
  • Performs routine inspections and baiting for rats in impacted neighborhoods.
  • Investigates suspected side-sewer breaks.
  • Educates communities about preventing and controlling rodent infestations when sewer rats are a concern.
Diagram of how rats travel from sewer systems into a toilet

How does a rat get in your toilet?

Rats get up into toilets by following the scent of food washed down drains from your home to the sewer system. While searching for food they can climb your home's stand pipe (the pipe that connects your homes drainage to the sewer). Unable to reach the kitchen sink, they can come up into the toilet bowl.

Keep lid down and squirt dishwashing liquid in toilet to reduce surface tension then flush the rat down

What do I do if I have a rat in my toilet?

  • Stay calm!
  • Keep the lid down so that it is unable to jump out.
  • Squirt some liquid dish soap in the toilet to help break the surface tension of the water. The soap degreases the oils on the rat's fur so it cannot stay afloat in the water.
  • Flush the toilet! The rat will usually go back down the drain the same way it came up. You may need to flush multiple times.
Keep your kitchen sink rinsed clean and use garbage disposals as little as possible.

Keep rats out of sewer pipes

Rats have a great sense of smell. They can follow the scent of food washed down drains by garbage disposals and dishwashing.

  • Keep your kitchen sink rinsed clean and use garbage disposals as little as possible.
  • Clean your drain! Use 1 cup of baking soda followed by 1 cup of vinegar and rinse with boiling water. You can also use 1 cup of bleach and rinse with boiling water.
  • Clean your kitchen sink drain monthly.
  • Never pour grease or oils down the drain.
Rat burrow tested with green dye

How do rats get into the sewers?

Rats get into sewer systems through broken or faulty side-sewers. The Seattle Sewer Baiting program can investigate a suspected faulty side-sewer connection when rats are a concern. A broken side-sewer can be identified by pouring a colored dye down a rat burrow.

If the colored water shows up in a nearby sewer then the side-sewer may have a break. When the dye test indicates a broken side-sewer, it is recommended that the homeowner hire a licensed contractor to make necessary repairs.

Green dye in sewer from burrow

What about rats in storm drains?

Occasionally, rats are seen going into a storm drain. In most cases the rats are ducking into the storm drain just to avoid a predator or from being seen. In some parts of Seattle, rats may gain access to the sewer if the sewer system is a combined drainage and sanitary sewer system.

Who do I call if I find a rat in my toilet?

If you find a rat in your toilet, you can report it to Public Health online at www.kingcounty.gov/rats or call 206-263-9566.

If you live outside of the city of Seattle and you find a rat in your toilet you may want to contact your city's public utilities department or your local sewer district. You can locate their contact information on your utility bill or do a search through their websites.