American pest control corporation Orkin released its ranking of the 50 most rat-infested U.S. cities in late October, stating that Los Angeles is now the most rat-infested city, followed by Chicago in second place, New York City in third place, and San Francisco in fourth place.
Orkin is one of the largest pest control companies in the world, headquartered in Atlanta, with more than 400 offices across the United States and operations in over 60 countries. Orkin’s annual ranking of rat-infested cities is cited by major U.S. media outlets each year as an indicator of urban sanitation conditions.
Orkin determined the rankings based on the number of new residential rodent control service requests received between August 20, 2024, and August 21, 2025. The company noted that Los Angeles’s warm climate, dense neighborhoods, and abundant food sources make the city an ideal breeding ground for rats.
The state of California has four cities listed in this year’s top 50, including Los Angeles (1st), San Francisco (4th), Sacramento (19th), and San Diego (24th). Rats tend to thrive in areas where food, water, and shelter are readily available. As the seasons change, rats and mice often seek warm places, squeezing through cracks and gaps into homes, which makes prevention especially important in the fall.
“Rats are not just a nuisance; they are opportunistic creatures,” said Ian Williams, a biologist at Orkin. “Once inside, they reproduce very quickly, turning a small problem into a large and costly one.”
American media have advised homeowners in high-risk cities like Los Angeles to inspect for holes, repair cracks, secure garbage bins, and contact pest control professionals when necessary.