FREMONT -- A ruse known as a "snake scam" has slithered its way from Union City to Fremont, police said Monday.

Fremont police were asking residents to be on alert after receiving reports on Saturday of a woman dressed as an animal control employee going door to door looking for a poisonous snake on the loose, police said.

The scheme is the latest in a series of East Bay home burglaries in which perpetrators pose as city employees. In recent weeks, scam artists have knocked on doors pretending to be utility workers in Oakland, tree trimmers in Hayward, and now animal control workers looking for snakes in Union City and Fremont.

Though the disguises are different, the scam works mostly the same way: the phony employee takes everyone from the home into the backyard to distract them while his or her partner goes inside and steals cash and jewelry. In one case in Hayward, $17,000 in items was stolen.

In Fremont, one home was burglarized on Moore Drive in the Cherry-Guardino area and a similar snake story was reported by homeowners in the Hillview-Montecity area of Niles, police said.

One of the suspects is described as white or Hispanic, about 5 feet tall, with a medium to heavy build and a pierced tongue. She was wearing a hat, dark colored gloves and a tan short-sleeved shirt with patches on the sleeves. She may be driving a silver Land Rover, police said.

Fremont city workers are required to carry a city-issued photo ID, and most drive city vehicles, police said. Authorities are asking anyone with information on the case or who may have captured the women on private video surveillance to contact police at 510-790-6900.

David DeBolt covers breaking news. Contact him in Richmond at 510-262-2728. Follow him at Twitter.com/daviddebolt.