Cockroach Control in Daly City, CA

Local Context

Two Cockroaches, Two Routes: One Through the Wall, One Up From the Crawl Space

German cockroaches live entirely indoors and travel with the building. They cluster tight to warmth, food and water — behind the refrigerator, under the sink, inside a dishwasher motor housing — and in the attached and multi-unit housing filling Westlake, Serramonte and the blocks near the BART station, they use shared wall voids and stacked plumbing chases to move between units. They get into a building on a grocery bag, a used appliance or a cardboard box, and their presence says nothing about how anyone keeps their kitchen.

The Oriental cockroach is the genuine Daly City specialty. It prefers cool, damp conditions, which describes a fog-belt crawl space almost exactly — bare soil, near-constant humidity, no dry summer to push it out. They live under the floor and in floor drains, water meter boxes and garage drains, then come up through pipe penetrations, the crawl-space hatch inside the garage, and gaps under doors, usually during the wettest stretch of winter or when the ground dries in late summer.

Construction gives both species short trips. A Daly City tract house stacks living space directly over an attached garage with the crawl-space access inside that garage, so the distance from a damp void under the floor to the kitchen above is a few feet of wall cavity. Add shared walls with the neighbors and one plumbing wall serving two units, and the practical unit of treatment stops being a single apartment.