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Woodlouse

life science Maturity 11-13 Next article →

Woodlice are small animals that live mostly on land.

Oniscidea all
Oniscidea all

Many people think they are insects, but they are actually crustaceans. This means they are more closely related to crabs and lobsters than to bugs. They belong to a group called Oniscidea. Woodlice are very important for the Earth. They are detritivores, which means they eat dead plant matter. By eating old leaves, they help turn dead plants into rich soil through a process called humification.

Oniscidea woodlouse morphology
Oniscidea woodlouse morphology

To survive on land, woodlice have developed special ways to work. They have a hard outer shell called an exoskeleton. As they grow, they must shed this shell in a process called a moult. Unlike most other animals, they shed in two steps. They lose the back half of their shell first. Then, they lose the front half a few days later. This might help them keep moving while they grow.

Oniscidea woodlouse morphology
Oniscidea woodlouse morphology

Females also have a special pouch called a marsupium. They carry their eggs in this pouch to keep them safe. The babies hatch as mancae and eventually grow more body segments.

Scientists believe woodlice have a very long history. They likely moved from the sea to the land a long time ago. Some research suggests they began moving during the late Paleozoic era. However, the oldest fossils we have found are from the mid-Cretaceous period. These fossils are about 100 million years old.

Oniscidea all
Oniscidea all

We have found these ancient fossils in amber from places like Spain, France, and Myanmar. These tiny fossils show us how woodlice lived a very long time ago.

There are many different kinds of woodlice in the world. Scientists have identified thousands of species, with some estimates reaching up to 7,000 species. They live in almost every environment on land. Some live in dark, damp places under rocks or logs.

Others live in very dry deserts. Some species even live in ant nests! They can even be used by scientists to check for pollution. Because they soak up heavy metals, they act as bioindicators for the health of an area.

Because they are so different, woodlice have many different names. Depending on where you live, you might call them a pill bug or a roly-poly. In Scotland, people often call them slaters. Some people even call them sow bugs or wood pigs.

Some woodlice can even roll into a tight ball to stay safe. This is a defense mechanism used to protect themselves or stay moist. This makes them very interesting to watch in a terrarium pet tank.

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🖼️ Images & Media (4)
File:Oniscidea all.jpg
Oniscidea all.jpg
File:Oniscidea woodlouse morphology.png
Oniscidea woodlouse morphology.png
File:Gråsuggor (Isopoda) - Ystad-2020.jpg
Gråsuggor (Isopoda) - Ystad-2020.jpg
File:Dysdera crocata.jpg
Dysdera crocata.jpg
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