House centipedes, scientifically known as Scutigera coleoptrata, are common arthropods often encountered indoors. These creatures are recognized by their yellowish-gray bodies and numerous long legs, which allow them to move with remarkable speed. While their appearance can be unsettling, a frequent question that arises is whether these multi-legged houseguests pose a danger to humans or pets. This article explores the nature of house centipedes to address this common concern.
Understanding the Threat
House centipedes are typically 1 to 1.5 inches long, but their many legs can make them appear up to 3 to 4 inches. They possess 15 pairs of legs, with the last pair often being notably longer, mimicking their antennae at the front. Their bodies are yellowish-gray with three distinct dark stripes running down their back.
House centipedes are venomous predators, using modified front legs called forcipules to inject venom into their prey. Bites to humans are rare and occur only if the centipede feels threatened or is handled roughly. Their small jaws struggle to penetrate human skin effectively.
When a bite does occur, symptoms are mild, resembling a bee sting, with localized pain, redness, and slight swelling. This discomfort subsides within a few hours. Severe reactions are uncommon, usually associated with allergic sensitivities similar to bee venom. For most people and pets, house centipede venom is not considered medically significant.
Why They Enter Homes
House centipedes originate outdoors, preferring cool, damp environments like those found under rocks, logs, or leaf litter. They are drawn indoors seeking shelter, especially during dry or cold weather. These arthropods are primarily nocturnal, meaning they are active at night and hide in dark, secluded places during the day.
Once inside a home, house centipedes actively seek out areas that mimic their natural, damp habitats. Common indoor locations include basements, bathrooms, crawl spaces, and closets, where humidity levels are higher. Their presence often indicates an existing pest problem, as they are drawn to homes by the availability of prey. House centipedes are insectivores, preying on a variety of other household pests such as silverfish, cockroaches, spiders, bed bugs, termites, and flies.
Coexisting or Controlling Them
While their appearance can be startling, house centipedes play a role in natural pest control by preying on other common household insects. This predatory behavior can help reduce populations of pests that are more damaging. Some people choose to tolerate them for this benefit, considering them beneficial residents.
For those who prefer to manage their presence, several strategies can help deter house centipedes. Since they seek moisture, reducing humidity in areas like basements and bathrooms through ventilation or dehumidifiers can make a home less appealing. Sealing cracks and gaps in foundations, walls, and around windows and doors can prevent their entry. Additionally, removing clutter both indoors and outdoors, such as leaf piles or stored items in damp areas, eliminates hiding spots. Addressing other insect infestations in the home can also reduce the food source that attracts house centipedes, encouraging them to seek sustenance elsewhere.