CRITTERS OPEN DOOR TO HEALTH RISKS : NIGHT VISITORS CARRY THREAT OF DISEASE.

Byline: Mary Schubert and Teresa Jimenez Daily News Staff Writers

Area health services officials have a warning for residents in the foothills: Put pet food away, keep crawlspaces closed and clear yards, or expect to find four-legged critters running through your home.

'Tis the season for mice, rats, opossums and other animals to stir and look for warm places to burrow away from the chill of winter.

Their next home could be yours if precautions aren't taken, health officials said.

The warning is for more than convenience sake. Although most people would like to avoid rodents in their home, they surely want to avoid getting endemic typhus.

Most cases of the disease have been reported in foothill communities, and residents living in or near the Santa Monica Mountains, Simi Hills and Santa Susana Mountains could be at risk, said Joe Ramirez, environmental health specialist for Los Angeles County's Department of Health Services.

``The animals do well in greenbelt areas. We have inadvertently created havens for rodents,'' Ramirez said. ``We recommend that people do not do anything to encourage the rodent population. We warn that these rodents are often away from predators (in residential areas) that would normally keep their population in check.''

Endemic typhus can be transmitted from rodents to fleas living on cats and rats, and people can get the disease when fleas bite.

The bacteria lives in the gut of fleas, and when they bite, they also tend to defecate, Ramirez said.

When their human victims scratch, they may cause the feces to mix with blood, Ramirez said.

``When you scratch, you make the transfer,'' Ramirez said. ``They're flulike symptoms and those symptoms, unfortunately, are shared by a multitude of conditions. It usually goes unreported.''

Residents in Los Angeles County who need more information may call [phone]. In Ventura County, call [phone].

Animal control workers routinely catch rats, pigeons, opossums, squirrels, bats, coyotes, raccoons, mice and skunks that have made themselves at home, said Officer Jerry White of the county Department of Animal Care and Control shelter in Castaic.

Rodents, marsupials and assorted birds and mammals are simply indigenous to Southern California, he said.

``No (area) is really immune from it,'' White said. ``We have coyotes who walk right down Lyons Avenue at night. It's not something that unusual.''

He recalled a recent incident in Valencia, where two opossums had nested in a garage. In another case, a pair of fruit bats had taken to hanging (upside down, naturally) under the eaves of a front porch, White said.

Gail Van Gordon, a public health entomologist with the county Department of Health Services, said small, burrowing rodents such as the deer mouse, also can spread the deadly hantavirus. Squirrels often carry sylvatic plague.