Cockroaches are common household pests that may spread bacteria, contaminate food and surfaces, damage property, and cause allergic reactions.

Most indoor cockroach infestations are caused by German cockroaches. They prefer warm, humid locations that are close to food and water, such as kitchens and bathrooms. Other cockroach species may occasionally be seen indoors, but are primarily found outdoors. These include the oriental cockroach, smokybrown cockroach, American cockroach, and Turkestan cockroach.

Cockroaches need only small amounts of food and water, so they can survive even in tidy homes. All food should be stored in insect-proof containers, and garbage should be stored in containers with tight-fitting lids. Remove clutter that could provide harborage for cockroaches. You will also need to seal up cracks and crevices where crumbs and food residue can collect, and where cockroaches can hide.

If you continue to see cockroaches after these steps, an insecticide may be warranted. Look for insecticide baits that are labeled for cockroaches. As with any pesticide, you MUST read and follow the label.

Sanitation and household insecticides are enough to resolve most problems with cockroaches, but if you have a severe infestation, you will need to contact a pest control service.

The District does NOT conduct residential or commercial pest control, but can identify suspected cockroach specimens and provide recommendations for control. If you’d like to schedule a technician visit, call 650-344-8592 or make a service request online.

For more information about cockroaches, visit the UC IPM webpage.

Page last reviewed: June 10, 2021