Ants, ants and more ants are marching into San Francisco Bay area homes, crawling up Christmas trees and making themselves a nuisance in unprecedented numbers because of winter's sudden onset.

"They give me the heebie-jeebies. Last night I came back to find the bathtub black with ants," said Elizabeth Darling of Menlo Park.The ants, lured by early December's sun and mild temperatures, weren't ready for the recent wet and cold weather. When the weather changed, they went scurrying inside houses, said Joe Neitzel, manager of Rose Exterminator Co.

The insects also were lured inside by Christmas trees, which drip sap and are adorned with candy canes, both of which they find irresistible, exterminators said.

Exterminators say the Argentine ants - the Bay area's most common variety - are hard to get rid of.