It just keeps raining and raining and raining -- and we all know what rain brings: besides lovely May flowers and extended flight delays, rain in San Francisco means.... ants. When their dirt nests get washed out, they come pouring up out of the earth and into your kitchen and bathrooms. Aaaaaagh! We hate ants!
During the 1998 El Nino, when we lived in a basement apartment, our bathroom looked like it had been tiled in black, that's how many ants there were. When we complained to the landlords, they shrugged and said, "all of San Francisco is an anthill." Others complained about finding ants that had climbed into the refrigerator water supply and frozen into the ice cubes, and a guy in the Marina turned on his shower and saw ants falling out. Ewwwwwww.
If you've got ant problems, the best insecticide is boric acid with a little sugar, or you can try and seal off their entry points in your house with caulk. Or detergent. Meanwhile, stop by the Cal Academy of Science's ants exhibit to learn more/be grossed out beyond belief.