Cockroaches are one of the most common household pests found in San Diego. They can live both indoors and outdoors and are attracted to three basic things: food, water, and shelter. They are primarily active at night, so seeing cockroaches during the daytime can sometimes indicate a significant population or disturbance of their hiding areas. 

Some cockroaches can reproduce surprisingly quickly. German cockroaches are particularly prolific and are the most common indoor cockroach species. Under favorable conditions, a German cockroach population can grow rapidly because females produce multiple egg cases during their lifetime. UC research notes that a single female and her offspring have the potential to produce tens of thousands of descendants in a year, although natural population pressures prevent all of them from surviving. 

This is why seeing a few cockroaches does not necessarily mean there are only a few present. Cockroaches hide during the day, and egg cases and young nymphs may be hidden in cracks, cabinets, appliances, walls, and other protected areas.

Cockroaches can hide in many areas around a home, including:

• Under refrigerators and stoves 
• Inside cabinets and drawers 
• Under sinks 
• Around plumbing 
• Behind appliances 
• In cracks and wall voids 
• Bathrooms and kitchens 
• Crawl spaces 
• Garages 
• Around drains 
• Water meter boxes 
• Sewer and drainage areas 
• Under leaves, mulch, wood piles and landscape debris 
• Around trash and garbage areas 

They generally look for areas that provide food, moisture, warmth and protection. 

Not all cockroaches are the same. Correct identification is important because different species have different habits and may require different treatment approaches. 

Size: Approximately ½–¾ inch
Color: Light brown/tan
Identification: Two dark stripes behind the head

German cockroaches are the species most associated with indoor infestations. They are commonly found in kitchens, bathrooms, cabinets, and areas near food and water.

They can hide inside appliances, cabinets, cracks and crevices and can spread throughout a home when populations become established.

German cockroaches reproduce much faster than the larger outdoor species, which is why an infestation can become difficult to control if it is not addressed early. 

Size: Approximately 1½ inches, sometimes larger
Color: Reddish-brown
Appearance: Large with fully developed wings

American cockroaches are one of the large cockroaches commonly found around San Diego. They are often associated with warm, damp areas such as sewers, drains, water meter boxes and other outdoor areas.

They can enter homes through openings around doors, plumbing, drains, foundations and other access points. 

Size: Approximately 1¼ inches
Color: Dark brown to black
Appearance: Broad, dark-colored body

Oriental cockroaches prefer cool, damp environments. They may be found around water meter boxes, trash areas, vegetation, crawl spaces, drains and other damp locations.

They can enter homes while searching for food, water or shelter. 

Size: Females are approximately 1 inch
Color: Dark brown to black, with lighter markings

Turkestan cockroaches are an outdoor species that has become very common in California. They can be found around wood piles, debris, irrigation areas, water meter boxes, pavement cracks, drainage pipes, storm drains and other protected outdoor areas.

They may occasionally wander inside homes, especially when outdoor populations are high, but they generally do not establish indoor breeding populations the way German cockroaches do. 

Size: Approximately ½ inch
Color: Light brown/tan

Brown-banded cockroaches prefer warmer and relatively dry areas and can be found in places such as furniture, closets, bedrooms and other areas throughout a home. They are less commonly encountered than German cockroaches in many residential situations. 

Cockroaches are more than just an unpleasant nuisance.

They can travel through sewers, garbage areas, drains and contaminated environments and can then move across food-preparation surfaces inside a home. This creates opportunities for bacteria and other microorganisms to be transferred to food and surfaces. San Diego County identifies cockroaches as a public-health concern because they can spread germs and contaminate food with their droppings. 

Cockroaches can also contribute to allergies and asthma. Proteins found in cockroach feces, saliva and shed body parts can act as allergens, and exposure can be particularly concerning for people who are sensitive to them. 

You don't always have to see live cockroaches to know they are present.

Common signs include:

• Live or dead cockroaches 
• Small cockroach nymphs 
• Egg cases 
• Droppings that resemble coffee grounds 
• Dark stains or smears along cracks and hiding areas 
• Shed skins 
• A strong or unusual musty/musky odor 
• Cockroaches appearing at night around kitchens or bathrooms 

Having cockroaches does not necessarily mean a home is dirty.

Cockroaches can enter a property in many ways. Outdoor species can move inside through:

• Gaps underneath doors 
• Cracks around the foundation 
• Plumbing penetrations 
• Drain openings 
• Utility penetrations 
• Garage doors 
• Cracks around windows 
• Water meter areas 
• Sewer and drainage connections 
• Landscaping that provides shelter next to the structure 

Cockroaches can also be accidentally brought inside in cardboard boxes, grocery items, packages, used appliances, furniture and other belongings. German cockroaches are particularly good at spreading between buildings by hitchhiking in items. 

At JBC Termite and Pest Control, treatment depends on the species of cockroach, where they are coming from, and the level of activity.

Gel bait can be an important part of cockroach control, particularly for indoor infestations.

The bait is placed in targeted areas where cockroaches are likely to find it. Cockroaches consume the bait and can transfer the active ingredient through the population.

Baits can be particularly useful when treating areas where widespread spraying is unnecessary. UC IPM recommends baiting as an important component of cockroach management and notes that it can take a week or longer before a noticeable reduction occurs. 

Depending on the species and location, targeted chemical treatment may also be appropriate.

Treatment can include targeted crack-and-crevice or exterior applications where permitted by the product label. We select treatment methods based on the specific situation rather than treating every cockroach infestation the same way.

For larger outdoor species such as American, Oriental and Turkestan cockroaches, controlling the exterior environment can be just as important as treating inside the home.

We look for areas such as:

• Water meter boxes 
• Irrigation areas 
• Landscape debris 
• Wood piles 
• Vegetation against the structure 
• Drainage areas 
• Cracks and openings around the home