• American cockroach (Periplaneta americana): Also known as a "water bug" or "sewer roach," this is the largest of the house-infesting roaches in the state of California. They prefer warm, moist environments like sewers and basements, often migrating into buildings from outdoors.

• Oriental cockroach (Blatta orientalis): A dark brown or black roach that prefers cooler, damp environments like basements, crawl spaces, and drains. They are often found trapped in sinks and bathtubs as they cannot climb smooth surfaces.

• Brown-banded cockroach (Supella longipalpa): Less common than the German cockroach, this species seeks out very warm, dry areas, often hiding near the electrical components of appliances.

• Turkestan cockroach (Blatta lateralis): A relatively new species to California, it is primarily an outdoor pest found in leaf litter and compost piles. However, it often invades buildings seeking cooler, damper conditions, and the males are capable of flying. 

Health risks:

Cockroaches are more than just a nuisance. They can pose several health risks to humans! 

• Disease transmission: Roaches can carry harmful bacteria such as Salmonella and E. coli on their bodies and in their feces. When they contaminate food, they can transmit diseases like salmonellosis, gastroenteritis, typhoid fever, and dysentery.

• Asthma and Allergies: The shed skin, saliva, and droppings of cockroaches contain allergens that can trigger asthma attacks and allergic reactions, especially in children. High concentrations of these allergens are frequently found in multi-unit housing.

• Contamination of Surfaces: By crawling over dirty areas such as garbage and sewage, cockroaches can spread pathogens to food preparation surfaces, plates, and utensils.

• Skin Irritation: The spines on a cockroach's legs can cause minor scratches, and their habit of chewing on dead skin can lead to irritation and infection around eyes and mouths.