Rats in La Jolla? Residents cry ‘outbreak,’ County says numbers are down

The roof rat — the most common type in San Diego County — like to climb, rather than burrow, and they live above ground.

In recent weeks and months, La Jolla Light has received several voicemails, e-mails and forwarded posts from from local residents about a perceived increase in the presence of rats in La Jolla.

And while one caller referred to the influx as an “outbreak,” the County’s Department of Environmental Health’s Vector Control Program actually reports a decrease in the number of complaints compared to recent years. City spokesperson Gig Conaughton said the County received 14 rat complaints or requests for service for the La Jolla area so far this year.

“The department received 19 in this time frame (January to October) in 2018; 34 in 2017; and 31 in 2016,” he said. “Overall, the County has received 1,421 rat complaints or requests for service in 2019.”

One reason for the decrease could be that residents, business owners and property management companies often contract with private pest control companies themselves, rather than call the County.

Signs of rat activity include:

  • stripped bark from plants and trees;
  • piles of cut snail shells under plants or piles of wood;
  • sounds in the attic, floor and walls;
  • rat droppings in garages, storage buildings or other sheltered areas;
  • rub marks caused by greasy rat fur;
  • damaged food containers;
  • signs of gnawing.

The type of rat likely to be found in La Jolla, Conaughton continued, is the roof rat (also considered the most common County-wide). Roof rats like to climb, rather than burrow, and they live above ground. They are gray or brown in color.

Rats, including roof rats, can carry and spread diseases to humans and animals, including plague from fleas that feed on infected rats, or from being bitten by an infected rat; food poisoning from food that has been polluted with rat urine or droppings; rat-bite fever from a bite from an infected rat; and parasites.

Factors that can influence the number of rat complaints the County’s Vector Control receives include rainy conditions (years with a lot of rain increase availability of food, which results in an increased rat population); colder weather (can sometimes cause rats to seek shelter indoors bringing them to the attention of residents); having access to food and shelter (when pet food is left out or fruit from trees is not picked and allowed to drop on the ground).

Conaughton explained: “The County’s Vector Control Program assists property owners with their rat control efforts by providing inspections and consultations. The County performs exterior inspections to educate property owners about structural weaknesses that may allow rats to enter structures. During these consultations, a rat control starter kit is provided to the property owner. These kits include an enclosed rat station, a rat snap trap, and an educational pamphlet with information for control measures focusing on exclusion and elimination.”

  • To request a free rat inspection: Call (858) 694-2888 or e-mail
  • For a County list of rat abatement steps: Visit