What bug has 30 legs? - The Environmental Literacy Council (2025)

Let’s cut to the chase: the most common answer to “What bug has 30 legs?” is the house centipede (Scutigera coleoptrata). While the word “centipede” implies one hundred legs, this particular species boasts precisely fifteen pairs, totaling thirty legs. But there’s so much more to these fascinating creatures than just their leg count. Prepare to delve into the world of the house centipede, its biology, its behavior, and its role in your home ecosystem.

Understanding Scutigera coleoptrata: More Than Just a Number of Legs

Appearance and Anatomy

The house centipede is easily identifiable by its brownish-yellow body, often marked with dark stripes. What truly sets it apart, however, is the disproportionate length of its legs compared to its body size. This gives them a spider-like, almost ethereal appearance. Each of their fifteen body segments has a pair of legs attached. Their last pair of legs is particularly long and thin, resembling antennae and sometimes causing confusion about which end is the head.

Habitat and Behavior

These creatures thrive in dark, damp environments. Inside homes, they are frequently found in basements, crawlspaces, bathrooms, and under sinks. They seek out these areas due to the higher humidity and the presence of their prey. Speaking of prey, house centipedes are nocturnal hunters, actively seeking out insects and other arthropods. Their speed and agility make them efficient predators.

Are They Harmful?

Despite their unsettling appearance, house centipedes are generally considered harmless to humans. They possess venom, which they use to subdue their prey, but their bite is rare and typically no more painful than a bee sting. In fact, they are more likely to flee than to attack.

Frequently Asked Questions (FAQs) About Centipedes

1. What does “centipede” actually mean?

The word “centipede” comes from the Latin words “centi” (hundred) and “pedis” (foot). However, this is more of a descriptive term than a literal count. Centipedes can have anywhere from 15 to 177 pairs of legs, depending on the species.

2. Are house centipedes insects?

No, centipedes are not insects. They belong to the class Chilopoda, while insects belong to the class Insecta. Centipedes are arthropods, meaning they have an exoskeleton, segmented bodies, and jointed appendages, just like insects. However, they differ in body structure and the number of legs.

3. Do house centipedes bite humans?

While they can bite, it is very rare. Their jaws are small and not designed to easily penetrate human skin. Even if they do bite, the venom is mild and rarely causes more than localized pain or swelling. It is often less painful than a bee sting.

4. Why are house centipedes in my house?

They are in your house searching for food and shelter. They feed on other pests, like roaches, silverfish, and termites. A house centipede sighting might actually be a sign of a larger pest problem.

5. How can I get rid of house centipedes?

The best way to control house centipedes is to reduce moisture in your home and eliminate their food source. Fix leaky pipes, use a dehumidifier, and seal cracks and crevices in your foundation. You can also consider using insecticides labeled for centipede control, but focus on creating an inhospitable environment first.

6. Are house centipedes poisonous?

Technically, house centipedes are venomous, not poisonous. Poisonous organisms are harmful if ingested, while venomous organisms inject toxins through a bite or sting. The venom of a house centipede is used to paralyze their prey.

7. Should I kill house centipedes?

This is a matter of personal preference. They help control other pests in your home, they can be seen as beneficial. However, if their presence bothers you, humane removal is an option, or preventative measures to discourage them.

8. What eats house centipedes?

Outside, birds, toads, and other larger insects prey on house centipedes. Inside, larger spiders may occasionally prey on them.

9. Where do house centipedes lay their eggs?

Female house centipedes lay their eggs in damp, dark places, such as under rocks, in soil, or inside cracks and crevices in your home. They can lay up to several hundred eggs throughout their lifetime.

10. How long do house centipedes live?

House centipedes can live for several years, potentially up to 3-7 years in ideal conditions.

11. What’s the difference between a centipede and a millipede?

Centipedes and millipedes are both arthropods, but they have distinct differences. Centipedes have one pair of legs per body segment, while millipedes have two pairs. Centipedes are also generally faster and more predatory, while millipedes are slower and primarily feed on decaying organic matter.

12. What is the leggiest animal on Earth?

The animal with the most legs is the millipede Eumillipes persephone, which can have up to 1,306 legs! This species was discovered in Western Australia.

13. What are some natural ways to repel house centipedes?

Diatomaceous earth is a natural desiccant that can help dry out their environment. Essential oils like peppermint, eucalyptus, and tea tree oil can also act as repellents. Regularly cleaning and decluttering your home can also make it less attractive to them.

14. How do I identify a house centipede bite?

House centipede bites are rare, but they can leave small red marks or punctures on the skin. There may be localized pain, swelling, and itching. Usually, the symptoms resolve themselves within a few hours.

15. Are house centipedes more active at certain times of the year?

They tend to be more active during warmer months when they are actively hunting for food. During colder months, they may seek shelter indoors to escape the cold.

Beyond the 30 Legs: Appreciating the Role of Centipedes

While many find them unsettling, house centipedes play a beneficial role in the ecosystem by controlling populations of other pests. Understanding their behavior and habitat preferences allows us to manage their presence in our homes effectively. It is also important to understand arthropod evolutionary processes, where the number of legs reduces over time. For more information on environmental topics, visit enviroliteracy.org, The Environmental Literacy Council’s website, which is a great resource.