If you have ever encountered a cockroach in a home or restaurant, there is a good chance it was a German cockroach. They’re especially common in urban areas and apartment complexes, where they thrive in warm, humid environments like kitchens, bathrooms and utility rooms.

“What is so intimidating is how fast they can infest a home,” says Tony King, a pest control expert with The Pied Piper. “In as little as two to three months, you might find yourself with hundreds of them concealed behind walls, under appliances or in cracks in the cabinets.”

In colder climates, German cockroaches are also liable to come inside seeking shelter. While it can be difficult to spot them at first, if you start seeing German cockroaches, it’s imperative to act quickly to prevent an infestation.

Here’s how to identify German cockroaches, plus how to get rid of them.

What are German Cockroaches

The German cockroach (Blattella germanica) is the most common species of cockroach worldwide, taking residence in people’s homes, restaurants, nursing homes and hotels. While initial thoughts assumed this roach is a native to Europe, its close relationship and looks to the Asian cockroach suggests its origins might be of southeast Asia. Quickly reproducing and resilient against pest control methods, the German cockroach is one of the most stubborn and difficult pests to deal with.

What Do German Cockroaches Look Like

Much smaller than the American cockroach, the German cockroach grows to less than an inch long, sporting a light-brownish or tannish coloration. With two black stripes on its back, six legs and a pair of antennas, this roach scurries quickly from to place to place. Although they do have wings, they rarely use them to fly.

German Cockroach Behaviors

Unlike some of their counterparts, German cockroaches prefer living indoors. In warm and tropical areas, they will spend more time outdoors. But with an inability to survive harsh and cold environments, expect to find them near or in human structures to live and reproduce.

“These roaches are usually brought into the home accidentally, hitchhiking a ride in on secondhand items or cellulose material,” says Emma Grace Crumbley, an entomologist with Mosquito Squad Plus. “Once inside, they’re highly attracted to warm areas, and can easily infest appliances like Wi-Fi routers, microwaves and ovens.”

Of the different cockroach species, the German cockroach is the truest of scavengers, eating almost anything they can get their metaphorical hands on. This includes things such as soap, book bindings, glue, toothpaste and pet foods in addition to all foods and crumbs left by people.

“Crumb remains from the meal, messy dishes and even grease splash behind your cooking stove can appeal to them,” says King. “They’re also very sensitive to humidity, so dripping faucets, drips on pipes or overnight-out pet water dishes are huge attractants.”

German Cockroach Life Cycle

The German cockroach goes through the typical three stages of metamorphosis: egg, nymph and adult. The most troublesome aspect of the German cockroach is their reproductive cycle. The females can produce more than 400 eggs during their lifetime, with their average lifespan only being three to six months.

With such a short lifespan, infestations grow quickly since the German cockroach can go from egg to adult in less than ninety days. With females reproducing often and in large numbers, along with a fast metamorphosis, the German cockroach can cause more problems for people than any other roach.

Signs of German Cockroaches

As German cockroaches are most likely to be found indoors, these signs will help guide whether they have penetrated your establishment.

  • Visual: If you see a cockroach flashing around food or water sources, there are most likely more around.
  • Droppings: German cockroaches leave small, brownish drops of stool where they eat and live.
  • Eggs: Females will carry around the egg cases a few days after birth, thus leaving behind these cases where they frequent.
  • Odor: German cockroaches leave a musty smell where populations congregate.

How to Get Rid of German Cockroaches

German cockroaches are commonly found indoors in warm and moist places with a consistent food source. Kitchens, bathrooms and basements are their favorites, hiding out in drains, cabinets and appliances.

Because they thrive in dirty, moist locations, the first step to getting rid of and preventing German cockroaches is good sanitation. Start off with a thorough cleaning, decluttering the house, sweeping behind the fridge, scrubbing greasy spots and vacuuming crumbs from drawers and corners.

If you find roaches or evidence of roaches on an item you want to keep, remove as many roaches and egg cases as you can and place the item in a trash bag, says Crumbley. If you can, freeze the item for at least 48 hours. Alternatively, leave it outside for a few days until there is no evidence of roaches.

Next, there are many ways to kill cockroaches: traps, baits, gels, powders and natural solutions. King recommends placing gel baits (like Advion or Combat) in areas where you’ve noticed activity, like under sinks, along appliances and around cabinet hinges.

“These slow-acting baits allow the roaches to return to the nest and share the poison, infecting the rest,” he says. In addition, he says to try insect growth regulators (IGRs), like Gentrol, which will prevent them from reproducing. However, with any baits, it’s critical to carefully follow instructions, to keep children, pets and other household members safe.

With their quick and efficient reproductive cycles, the German cockroach is difficult to control. It only takes a few surviving eggs to replenish an infestation. So, if your efforts appear unsuccessful, consult with a pro.

“For German roach infestations, in particular, DIY solutions typically do not work,” says Crumbley. “These roaches are small, fast, and reproduce quickly, so the quickest and most efficient way to get rid of German cockroaches is to call a pest control professional for assistance.”

German Cockroach Safety

The dirty habits of the German cockroach make them a particular issue for homes and businesses. Their eating habits can contaminate food. Their droppings and pheromones can cause allergy and asthma problems. And they can leave behind bacteria and pathogens harmful to people. The dangers cockroaches can create demand immediate and deliberate action.

FAQ

How fast do German cockroaches reproduce?

Pretty quickly. “One female can carry about 40 eggs at a time, and produce hundreds in just a few months, which is why infestations grow so fast,” says Trenton Frazer, lead entomologist at Aptive Environmental.

How can I prevent future infestations?

Unlike other cockroaches that wander into your home from the outdoors, German roach infestations are almost always the result of accidentally bringing them inside, says Crumbley. So, the best way to prevent future infestations is to thoroughly check used items before bringing them into the home, and act quickly if German roaches are found by reaching out to a pest control professional.

It’s also important to keep your house clean, especially the kitchen and bathrooms. Fix water leaks promptly, store food tightly, don’t leave food out overnight (including pet food), take out the garbage nightly, dehumidify damp areas and vacuum regularly. Also, it’s helpful to seal off entry and hiding points with caulk, including gaps along baseboards, holes around pipes and spaces next to electrical outlets.

“Preventing future infestations is as simple as making your house as unwelcoming to cockroaches as possible,” says King. “I also recommend that customers place sticky traps in kitchen corners and under sinks as warning signs. Regular maintenance and vigilance go a long way in keeping roaches away.”

Finally, if you live in an apartment or townhome, prevention may also involve communicating with neighbors and HOAs. “Infestations of German roaches can easily spread to adjacent rooms and units,” says Crumbley.

About the Experts

Tony King is a pest control expert and founder of The Pied Piper, a pest control company serving the London, England, area for more than 25 years.

Emma Grace Crumbley is an entomologist at the national pest control franchise Mosquito Squad Plus and a self-described bug nerd who uses her expertise to educate people about the fascinating world of bugs.

Trenton Frazer is a lead entomologist at Aptive Environmental. He has worked in the pest control industry for 20 years, providing pest control solutions and educating the public on pest prevention and management.

Additional Cockroach Resources

For more information about cockroaches and what it means when you find this pest in your home or business, check out these pest control articles.

Sources

  • https://www.epa.gov/managing-pests-schools/cockroaches-and-schools
  • https://extension.umn.edu/insects-infest-homes/cockroaches#german-cockroach-137710