Wood cockroach in the house: is it an infestation?
A wood cockroach in the house is an outdoor cockroach that has come inside by accident. It lives outdoors, does not breed indoors and is not a pest, according to the Dutch Knowledge and Advisory Centre on Animal Pests (KAD). You can simply put it back outside. Not sure whether it might be a German cockroach after all? Look at when and where you see it: that is what this article is about.
In this article
What is a wood cockroach?
Wood cockroaches are small cockroaches of the genus Ectobius that live outdoors, which is why they are also called garden cockroaches. They are about 0.5 to 1.3 cm long and each species has its own spot or marking on the shield behind the head. They are active during the day and at dusk, unlike the cockroaches that live in homes.
How does a wood cockroach get into the house?
By accident: through a gap, an open window or with firewood. You then see one or two, mainly in summer and near a window. Some wood cockroaches are good fliers, such as the amber wood cockroach, and that is how they also come in through an open window.
Is a wood cockroach a problem in the house?
No, it is not a pest. According to the German Environment Agency (Umweltbundesamt), wood cockroaches do not infest food and cannot breed inside buildings. The Baden-Württemberg State Health Office writes that they do not carry germs. That makes them very different from the German cockroach, which can spread bacteria such as salmonella.
Can wood cockroaches breed in your house?
No. Wood cockroaches cannot survive indoors for long (KAD) and leave by themselves in autumn (Baden-Württemberg State Health Office). A wood cockroach in the house remains a single visitor.
How can you tell a wood cockroach from a German cockroach?
Look at when and where you see it. You see a wood cockroach during the day or at dusk, in summer and near a window. A German cockroach shies away from light: you see it at night in the kitchen or bathroom, and it darts away when the light goes on. Close up, the German cockroach has two black stripes on the shield behind the head and a full row of spines on its upper legs.
| Wood cockroach | German cockroach | |
|---|---|---|
| Length | about 0.5 to 1.3 cm (wood cockroaches together) | about 1.1 to 1.5 cm |
| Marking | each species its own spot or marking behind the head | two black stripes behind the head |
| Active | during the day and at dusk | at night, shies away from light |
| Where and when | near a window, mainly in summer | kitchen and bathroom, also outside summer |
| Spines on the upper legs | none or a few | a full row |
| Breeds indoors | no | yes |
What should you do with a wood cockroach in the house?
Put it back outside, for example with a glass and a piece of card. According to the KAD, controlling them with a product is neither necessary nor desirable. So you do not need a trap or a spray for a wood cockroach; keep windows and gaps closed in summer if you see them more often.
When is it an infestation after all?
When you see cockroaches at night in the kitchen or bathroom, also outside summer, and you find small black droppings or empty egg cases. Then you are dealing with a species that lives indoors, such as the German cockroach. Read how to tell a German or Oriental cockroach apart and how to get rid of cockroaches.
Sources: Dutch Knowledge and Advisory Centre on Animal Pests (KAD), wood cockroaches; German Environment Agency (Umweltbundesamt), cockroaches (2026); Baden-Württemberg State Health Office, cockroach information (2019).
