Washington Species
Aernophilus bipunciticeps is the soil centipede species found in Washington. These centipedes have between 31 and 177 pairs of legs and can burrow as deep as two and a half feet into the ground. They are typically yellowish brown with a partially transparent exoskeleton. They can grow to 2 inches long and are typically very thin--less than 1/4 inch wide.
Centipede Behavior
Soil centipedes are generally skittish and avoid human contact. Female centipedes lay eggs and fiercely guard them, according to the book, "National Wildlife Federation Field Guide to Insects and Spiders of North America." Humans who come into contact with females who are guarding eggs might be bitten. Soil centipedes consume primarily larvae and worms. They also occasionally eat detritus, decaying organic matter.
Location
Washington's soil centipedes are commonly found in piles of leaves, under tree bark and in rubbish piles. They prefer moist locations and frequently take up residence in areas located near bodies of water. They are also common in gardens.
Role in Ecology
Although many people are tempted to kill centipedes because of their bizarre appearance and ability to bite, these arthropods play a vital role in the ecosystem. By eating worms and larvae, they prevent pest overpopulation. They also help return nutrients to the soil by eating detritus, making them valuable additions to a garden.