Pest Control/Roaches


Hi Jack:

I've had a consistent problem with roaches--finding 1 or 2 a month, especially in warm weather after sunset. I live on the 2nd floor of a Southern California condo and find dark brown roaches usually 1-1/2 to 2 inches in length, most often in the bathroom (either in the sink or on the floor) or occasionally on the living room carpet. Once one was even crawling on the living room ceiling! How do they get in? How do I keep them out? I've never found one in the kitchen or cabinets, so they're not after food.

What do you think? Thank you!


In warm climates like S. Cal. cockroaches can live outside but more often roaches are confined to buildings. These are tropical insects so don't do well in dry/cold areas. See for general info about roaches and roach control. Older, multi-family buildings are particularly prone to cockroach infestations, even relatively clean ones. Your best option is to treat the entire building with cockroach baits (see as this has the best chance of reducing the population. You may also want to use the weatherized baits for outside, around the foundation.

Since you are finding these in the bathroom they may be entering the building in search of water, especially during dry weather.

Post a follow-up if you have questions.

Jack DeAngelis  

Pest Control

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Jack DeAngelis


I can answer questions about the control of pest insects, spiders, mites and related arthropods. These household pests include termites, carpenter ants, powderpost beetles, nuisance ants, bed bugs, cockroaches, fleas, wasps, and many others. I can also answer questions about using pesticides and other pest control tools such as baits and traps.


I am a retired university extension entomologist. I've taught and conducted research in urban and agricultural entomology. I've published over 70 extension publications, 20 research publications and several books about insects.

Ph.D. in Entomology

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