Winter Rodent Activity

We have been receiving reports of increase mice and rat activity throughout the community. This recent surge in rodent activity is not unique to just CHOA – Contra Costa County also confirmed that it is currently noticing a big increase in the number of requests it’s getting for rat and mouse service.

Per the County’s Mosquito and Vector Control District, an increase in rodent activity around the start of fall makes sense as it’s that time of year when temperatures get cooler and rats and mice would rather be inside where it’s warm and dry than outside where it’s cool and sometimes rainy.

The county has the following recommendations for making your property less attractive to rodents:

Remove places where rats and mice can find shelter outside

• Remove dense shrubbery.
• Trim any climbing vegetation at least four feet from your home’s roof and walls.
• Store wood and lumber piles at least 18 inches above the ground and at least 12 inches away from any structure.
• Install wire mesh around the bottom of outdoor structures including sheds and make sure shed doors are completely closed at night.

Remove potential food or water sources for rats and mice

• Harvest fruit and nuts as they ripen.
• Pick up fallen fruit and nuts daily.
• Bring in pet food and water bowls at night.
• Place a tarp under bird feeders to remove fallen bird seed each night.

The Mosquito and Vector Control District public health service involves inspection and advice regarding rodent activity. County residents can request service by phone at 925-685-9301 or online at www.contracostamosquito.com. During the rat and mouse service, the District employee will:

• Inspect the exterior of the property looking for potential food or shelter opportunities for rats and mice
• Look for evidence of rats or mice including droppings, nesting materials, rub marks, and evidence of gnawing
• Look for evidence of damaged vent screens and other openings, where a rat or mouse could easily gain access to a home’s interior
• While District employees do not inspect the interior of the home, the employee will inspect the garage as long as the garage door is open.
• The employee will look for the same evidence types listed above.
• While inspecting the garage, the District employee will also look for pet food, grass seed, and other items commonly kept in a garage that should be stored carefully to prevent access by a rat or mouse.

Following the inspection, the District employee will make recommendations on what the resident should do to reduce the risk of rats and mice on their specific property. The recommendations are written down and provided to the resident.