Why Do Cockroaches Have Such Large Families?

Summary: Roaches are disgusting pests, but how do they have such large families? This blog explores the life cycles of the 4 most common cockroach species to learn more about their reproductive rates. The species are: American roaches, German roaches, Oriental roaches, and brown-banded roaches. Pointe Pest Control provides efficient roach control for every season.

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February is the month of love, but romance gets all the love (pun intended) this time of year. Love between friends and family is just as important, in our humble opinion. When we think of family within the pest world, one immediately comes to mind: cockroaches.

Roaches have huge families. Females produce eggs in cases called oothecae, and all roaches have the same life stages (egg, nymph, adult). Where there’s one roach, a hundred more are hiding nearby. But why do these pests multiply at such a rapid rate? Let’s find out by exploring the life cycles and reproductive rates of the 4 most common roach species in the country.  

American Cockroaches

Life Span: 1 year

Female American roaches produce anywhere from 6 to 14 oothecae total. Each ootheca has about 15 eggs inside, so an American roach can create over 200 eggs in its lifetime! Once the female roach produces an ootheca, she attaches it to a hidden surface using her saliva. The eggs hatch a little over a month later, and the nymphs molt 10 to 13 times as they grow into adults.

American roaches are very populous when they live in an ideal environment. They love living outdoors when it’s damp, but they’ll invade rooms that have abundant food and water. Commercial buildings — restaurants, warehouses, etc. — see more American roaches than houses. However, these pests are known to invade plenty of houses after a good rainstorm! 

German Cockroaches

Life Span: 100-200 days

German roaches produce even more offspring, despite their average oothecae count of 4 to 8 total. That’s because each ootheca (carried by the mother) contains 30 to 50 eggs! The eggs hatch less than a month later, and molt 6 to 7 times over the 2 months it takes for them to grow. Female roaches start reproducing less than 2 weeks after becoming adults.

Although they rarely fly, these roaches are smaller and faster than the other varieties mentioned here. German cockroaches are some of the fastest-reproducing roaches. An infestation grows out of control very easily since females don’t need males in order to create eggs. They exhibit parthenogenesis to produce female children without a fertilization process. 

Oriental Cockroaches

Life Span: Up to 1 year

Oriental roaches create up to 15 oothecae in their lifetimes. Each ootheca is carried by the mother for 5 days and deposited in a warm area. The 16 eggs inside the ootheca hatch up to 3 months later, then the young roaches molt 7 times in the year it takes them to grow. Since the adult roaches die 6 months later, they need to work quickly to expand their families.

These moisture-loving roaches are extremely tolerant of the cold. They love the rain and only invade homes and buildings when they need a humid habitat. Oriental roaches are most troublesome in the summer since they’re searching for an indoor reprieve from the heat. These black insects are often found in crawlspaces, drains, and garbage cans.

Brown-Banded Cockroaches

Life Span: About 200 days

Brown-banded roaches are average in terms of their oothecae production. Females create about 14 oothecae total, each one containing 14 to 17 eggs. The mother carries her ootheca for about 30 hours, then glues them to furniture with her saliva. The eggs hatch 3 months later, or sooner in hot temperatures. The young roaches molt 6 to 8 times as they take 8 months to grow. 

One of the unique characteristics of brown-banded roaches is that they don’t need as much moisture as other roaches. They actually reproduce more in the summer when it’s typically the driest outside, as the high temperatures increase their energy levels. Female brown-banded roaches also despot their egg cases in clusters when their population is huge.

What Have We Learned Here?

So, with all of this being said, we’re still wondering why roaches have such large families? The main reason is that the 4 most common species produce a steady output of young roaches. When each egg case contains a lot of eggs, and the female roach produces quite a few oothecae total, it’s easy for the roach population to get out of hand.

The good news is that roaches have an Achilles heel: water. They can go a month without food, but they can only go up to a week without water. That’s why we see roaches in humid settings, like bathrooms and kitchens. 

Roach invasions are best combatted with professional pest control since they have the strongest treatments. Any roach is a likely sign of an invasion. But if you see light-colored roaches — roaches get lighter when they molt — there’s a growing family of cockroaches nearby.

Nobody Does Family-Friendly Pest Control Like Pointe

Efficiency and safety are not mutually exclusive in the services from Pointe Pest Control. Our licensed technicians use the proper application methods for every treatment. We understand the importance of safety when it comes to pest control. After all, you don’t want a bunch of chemicals sprayed around your home with reckless abandon!

When you receive quarterly services from Pointe, you can be sure that our team will treat your home as if it’s our own. We carefully apply targeted treatments to activity hotspots, then provide a protective barrier around the house to keep out any future invaders. No matter your pest problem, Pointe has the long-term solutions for you. Contact us for more information on our effective pest control services today!

Citations

American cockroach life cycle. (n.d.). Orkin. Retrieved January 30, 2025, from https://www.orkin.com/pests/cockroaches/american-cockroaches/american-cockroach-life-cycle 

Brownbanded cockroach. (n.d.). OSU Extension: Insects and Arthropods. Retrieved January 30, 2025, from https://extension.okstate.edu/programs/digital-diagnostics/insects-and-arthropods/brownbanded-cockroach-supella-longipalpa/

Learn about roach behavior and their purpose. (n.d.). Terminix. Retrieved January 30, 2025, from https://www.terminix.com/cockroaches/learn-about/

McCanless, K. (2021, April). Oriental cockroach. University of Florida: Featured Creatures. Available at https://entnemdept.ufl.edu/creatures/urban/roaches/oriental_cockroach.htm (Accessed on January 30, 2025). 

Where do brown-banded cockroaches lay eggs?. (n.d.). Orkin. Retrieved January 30, 2025, from https://www.orkin.com/pests/cockroaches/brown-banded-cockroaches/brown-banded-cockroach-eggs