German Cockroaches


Adult German cockroaches are about ½-inch long and tan to light brown. While adults have wings, they do not use them to fly. One of the best ways to identify these cockroaches is to look for two dark, parallel lines that run from the back of the roach’s head to its wings, often referred to as “racing stripes” by laymen entomologists. Sometimes homeowners will see white cockroach adults.  These are not a different species or albino cockroaches, but are actually newly molted adults whose cuticle has not hardened and changed to its normal color.

Nymphs are similar in appearance to adults except that they are smaller and lack wings.


German cockroaches are most active at night as they move around looking for food and moisture. During the day, they seek refuge in cracks, crevices and other dark and humid environments that provide protection. When German cockroaches are seen during the day, that usually indicates a very heavy population and conditions that require them to move from one harborage site to another seeking the things they need to survive.

Cockroaches have the potential to taint foods and mechanically transmit disease organisms that occur on their bodies. It is reported that German cockroaches can potentially transmit numerous organisms that cause diseases, but perhaps the most serious medically related problem they cause is allergic reactions.


The best way to describe the German cockroach diet is that they will eat almost anything that is starchy, sweet and greasy, or has protein. In other words, they are scavengers that will eat wastes, food crumbs, garbage, pet food left around their environment and sometimes even glue used for binding the pages of books.


Their habitat can be just about any place where they have moisture, warmth, protection, little or no light, and is located close to a food source. Usually, German cockroaches are the most common species of cockroach found in homes, restaurants and other commercial buildings. In places where German cockroach populations are very large, one may find these cockroaches living in clusters out in the open and in plain sight.


The German cockroach has three life stages – egg, nymph and adult.  Their reproductive potential is tremendous since they can complete an entire life cycle in about 3-4 months and mate constantly. In fact, a population of German cockroaches is very likely to have many overlapping generations present at any given time. Like many other species of cockroaches, the female German cockroach produces a case of about 40 eggs, which she carries in her abdomen and deposits in a protected location shortly before the eggs begin to hatch.


Presence of the nymphs, adults, egg cases, fecal droppings, and odors from the cockroach’s bodily secretions are signs of their activity. Since they are photophobic, go into your kitchen late at night, turn on the lights, and see if any cockroaches scamper around looking for a dark place to hide.


Some effective tips to help prevent German cockroach problems include:

  • Don’t bring them inside your house. Check grocery bags, cardboard boxes or other articles before bringing them inside.
  • Keep the house clean by removing any food scraps, using the garbage disposal, keeping the sink clean, regularly emptying the trash, using garbage bags and keeping the trash cans clean. Don’t leave pet food out overnight.
  • If necessary, put foods in containers with tight-fitting lids or place foods in the refrigerator.
  • Seal openings around pipes or electrical lines that lead into wall voids and cracks and crevices along floor baseboards, window and door frames
  • Eliminate water sources by repairing any plumbing leaks and removing standing water. Don’t forget about the water that collects in the refrigerator pan
  • Use your vacuum to keep things clean and to remove spilled foods.
  • Remove clutter and be sure to never let newspapers, grocery bags or other debris pile up. From time to time, move or discard things that are rarely relocated and see what you find.


German cockroach control products are almost always a necessary component of an integrated pest management plan. Such products may include:

  • Insect growth regulators (IGRs); these products are formulated to help reduce the reproduction capability of German cockroaches. Also, using IGRs increases the German cockroach’s appetite, and they are more likely to consume bait products.
  • Baits; cockroach baits are generally the most frequently used and also the most valuable products since they are easy to apply and are very effective in combating cockroaches. Depending upon the formulation, baits can be used both inside and outside.
  • Liquid, dust, and aerosol insecticide sprays are effective when applied to cracks, crevices, and other harborages. However, anytime insecticides are used, the applicator must adhere to the directions and instructions printed on the product’s label. Room foggers are usually an ineffective product to use for German cockroach control.