PLEASANT HILL -- Carol Anderson recently found an uninvited -- and unwelcome -- guest on her front lawn.
"I have squirrels and every day I'd go out and throw a few peanuts to the squirrels," said Anderson, who has lived in her Patterson Boulevard home in the Poets Corner neighborhood for nearly 50 years. "All of a sudden there was a rat waiting for his turn."
Anderson, 78, said she hadn't seen a rat in her neighborhood in 25 years -- but a few days later, she saw another. She believes work at the long vacant residential property behind her home disturbed a rat colony.
"The backyard was overgrown and that's the kind of place that rats and mice and raccoons like," she said. "When they plowed it all over and cut down the trees the rats had to go somewhere."
Anderson called the city and the Contra Costa Mosquito & Vector Control District for help. She hasn't been entirely satisfied with either agency's response.
The city's code enforcer, Anderson contends, offered little assistance beyond suggesting that she hire a private pest control firm. But Anderson believes the city should have required the contractor working on the vacant property to remove any rodents that may have been living in the vegetation in the back yard. Planner Greg Fuz, who oversees code enforcement for Pleasant Hill, could not be reached for comment.
Rodents pose a threat to public health because they can spread disease. Contra Costa Mosquito & Vector Control District baits for rodents in sewers and public areas such as parks and canals. Although the district advises residents on how to prevent and control rat and mouse infestations, it doesn't bait or trap rodents at private homes.
In 2012, the vector control district responded to 598 requests for free inspections from residents and business owners in the county. The district prepares detailed reports identifying the type of rat and how the animals are getting into the building. Last week, a rodent technician inspected Anderson's house. The technician, who reportedly discovered rat droppings and chewed wires in Anderson's garage, doesn't believe the rodents came from the vacant property, according to Deborah Bass, district spokeswoman.
Bass said two rat species are found in Contra Costa County -- so-called roof rats, which nest in trees and places high off the ground, and Norway rats, which prefer the sewers and other low-lying areas.
"(Rats) need food and they need a place to stay, so our general recommendations are don't have a bird feeder and make sure you pick up all your fallen fruit, although rats will go into the trees," Bass said.
Even though Anderson saw the rats outside, Bass said the district isn't responsible for collecting them. However, the technician left notices on neighboring houses alerting residents to rodent activity in the area and asking them to call the district if they want an inspection, she said. The district also works with cities to eradicate rodents; for example, if a city takes possession of a vacant property that harbors rats or mice, the district will put down bait, Bass said.
"If we go to a property and we see problems we believe the city should be involved in we will call them," she added.
It's unclear what conditions would prompt Pleasant Hill to request assistance from the district.
As for Anderson, who likely faces a hefty fee if she hires an exterminator, the rodent technician emptied the bird feeder she had in her yard. Although she now knows that her 40-year-old lemon tree is an all-you-can-eat buffet for rats, Anderson refuses to cut it down.
"I won't feel quite the same about it anymore," she admitted.
Have a rodent problem? Contact the Contra Costa Mosquito & Vector Control District for a free inspection at 925-771-6196.
Lisa P. White covers Martinez and Pleasant Hill. Contact her at 925-943-8011. Follow her at Twitter.com/lisa_p_white.