What city has the most rats and mice in the US?

Key takeaways

• Rodents can cause severe damage to homes by chewing on wires and insulation. They also pose serious health risks and carry several diseases. 
• Western Exterminator identified some of the cities with the most rats, including Los Angeles, San Francisco, Palm Springs, Sacramento, and Seattle. 
• Human activity and climate change have caused rodent populations to increase in urban areas. 
• Signs of a rodent infestation include droppings, strange noises, foul odors, gnaw marks, nesting materials, and tracks. 

Rodents are more than just an unsightly nuisance—they pose significant risks to property and health. Not only are they carriers of various diseases, but their ability to gnaw through wires and insulation can lead to costly damage. That’s why it's important for homeowners to stay on top of pest activity and call for a rodent exterminator when needed.

At Western Exterminator, we used service data from all our branches to identify the most rat-infested cities on the West Coast. Some cities with the most rats include Los Angeles, San Francisco, Palm Springs, Sacramento, and Seattle. Keep reading to see if your city made the cut.

What city has the most rats on the West Coast? 

Several cities have seen an increase in rodent activity in recent years. As cities expand, they provide abundant food sources in the form of garbage, waste, and easily accessible shelter in buildings and alleys. Climate change also plays a role, as rising temperatures can extend the breeding season for rodents and alter their natural habitats, allowing them to explore new areas for food and nesting. 

Is your city on the list? Take a look at the most rodent-infested cities on the West Coast*: 

1. Los Angeles, CA
2. San Francisco-Oakland-San Jose, CA 
3. Palm Springs, CA
4. Sacramento-Stockton-Modesto, CA
5. Seattle-Tacoma, WA
6. San Diego, CA
7. Santa Barbara-San Marcos-San Luis Obispo, CA
8. Bakersfield, CA
9. Portland, OR
10. Monterey-Salinas, CA
11. Fresno-Visalia, CA 
12. Reno, NV
13. Eugene, OR
14. Boise, ID
15. Phoenix, AZ
16. Tucson, AZ
17. Medford-Klamath Falls, OR
18. Chico-Redding, CA
19. Twin Falls, ID
20. Bend, OR 

Are rodents in my home? 

Rodents can be sneaky, but rats and mice often leave behind traces of their activity. Here are some signs of rats to look for: 

• Droppings: One of the most noticeable signs of a rodent infestation is their droppings. Rat droppings are about the size of a raisin, while mouse droppings are smaller and more pellet-like. You might find these droppings near food sources, along walls, or in hidden corners. 
• Gnaw marks: Rodents constantly need to gnaw to keep their teeth from growing too long. Look for gnaw marks on furniture, walls, wires, or food packaging. Due to their size, rats tend to leave larger marks than mice. 
• Nesting materials: If you notice shredded paper, fabric, or other materials in hidden areas, it could indicate that mice or rats are nesting nearby. They often use these materials to create warm, cozy nests. 
• Tracks: Small footprints might be found in dusty areas or attics. If you suspect rodent activity, sprinkle a little flour on the floor and check for footprints the next day. 
• Strange sounds: Rodents are often active at night, so listen for any scratching, scurrying, or squeaking sounds coming from inside walls, ceilings, or attics, especially during dusk or nighttime. 
• Foul odors: A strong, musky smell can indicate a rodent problem. This scent comes from their nests, droppings, and urine. 

Protect your home from rodents with Western Exterminator 

If you live in one of the most rat-infested cities, it’s important to stay vigilant. At Western Exterminator, our technicians are trained to find where rodents are hiding and know how to eliminate them. With a custom mouse control or rodent control plan in place, you can help protect your home no matter what city you’re in. 

*The cities listed are based on Nielsen’s Designated Market Areas (DMAs). A DMA may include multiple nearby cities and surrounding suburbs that function as one larger media market. For this reason, some entries may list more than one city together.