Finding a centipede scurrying across your floor can be pretty scary. With all those legs moving at once and their lightning-fast speed, it’s natural to wonder if centipedes are dangerous to you and your family.
The good news is that most centipedes pose very little threat to humans, but there are a few things you should know to stay safe.
What Are Centipedes and How Do They Bite
Centipedes are predatory arthropods that have been around for over 400 million years. Despite their name meaning “hundred feet,” they don’t actually have 100 legs. The number of pairs of legs is an odd number that ranges from 15 pairs to 191 pairs, with each body segment having one pair of legs.
Here’s something interesting: centipedes don’t really “bite” like other insects do. Instead, they use special modified front legs called forcipules that work like pincers. Their fangs are a pair of modified legs called forcipules which contain venomous glands. These forcipules grab onto prey and inject venom to paralyze it.
Centipedes are nocturnal hunters, which means they’re most active at night when you’re sleeping. They prefer dark, damp places and usually try to avoid humans. Most of the time, centipede encounters happen by accident when people reach into woodpiles, under rocks, or other hiding spots where centipedes like to hang out.
Most Centipedes Are Not Dangerous to Humans
If you’re wondering if centipedes are dangerous, here’s some reassuring news: the vast majority of centipede species are basically harmless to people. There are approximately 3500 identified species of centipede, but only 15 (less than 0.5%) is thought to be clinically significant in regards to patient discomfort, morbidity, and mortality.
The most common type you’ll find in homes is the house centipede. These guys are actually pretty wimpy when it comes to causing harm. When given the chance, house centipedes prefer to quickly retreat from danger rather than bite. Typical symptoms from a house centipede bite are slight pain and swelling as their weak jaws rarely allow them to break skin.
For most centipede species, the worst side effects from centipede bites are usually mild pain and swelling. The venom that works great on small insects just isn’t strong enough to cause serious problems for something as big as a human. These chemicals harm small insects but pose no serious threat to humans.
The Few Dangerous Species You Should Know About
While most centipedes aren’t a big deal, there are a couple of species that can pack a more serious punch. The main ones to be aware of are the giant centipedes, particularly those in the Scolopendra family.
The biggest centipede in North America is Scolopendra heros, commonly known as the Arizona desert centipede, giant desert centipede, giant Sonoran centipede, Texas black-tailed centipede, Texas redheaded centipede, and giant redheaded centipede. This beast can grow up to 8 in (200 mm) in the wild, and even longer in captivity. You’ll find these mainly in the southwestern United States and northern Mexico.
Even bigger is Scolopendra gigantea, also known as the Peruvian giant yellow-leg centipede or Amazonian giant centipede, which is the largest centipede species in the world, with a length exceeding 30 centimetres (12 in). This South American giant is capable of hunting bats, birds, and small mammals.
These larger species are much more aggressive than house centipedes and will readily defend themselves if they feel threatened. The question of whether centipedes are dangerous becomes more relevant when dealing with these giants.
Symptoms and Effects of Centipede Bites
The symptoms you experience from a centipede bite depend mainly on the size of the centipede and how much venom it injects. Smaller variants of centipedes produce nothing more than a painful, localized reaction, not unlike a bee sting. Larger species, however, administer more venom through a bite and can produce more extreme pain.
For most centipede encounters, you can expect:
- Pain, redness, and swelling begin immediately upon being bitten. These symptoms may last anywhere from several hours to several days
- Two puncture marks in a V-shape from the forcipules
- Local swelling and possible itching
With larger centipedes like the giant desert centipede, symptoms can be more intense. Symptoms of a giant desert centipede bite include intense pain, inflammation, redness, and swelling. Generally, these symptoms subside in a matter of several hours; however, bite victims that are more sensitive to the centipede’s venom may experience vomiting, dizziness, headache, and irregular pulse rates.
In very rare cases, more serious complications can occur, including tissue death at the bite site or secondary infections. Some people might also experience allergic reactions, especially those who are already allergic to bee or wasp stings.
How Rare Are Serious Centipede Injuries and Deaths
When people ask if centipedes are dangerous, the statistics are actually quite reassuring. Serious injuries and deaths from centipede bites are extremely rare. Studies have shown that between 1979 and 2001, only 6 deaths in the USA are attributable to centipede bites, compared to 1060 fatalities from bees, wasps, and hornets.
Globally, the numbers are similarly low. As of this date, there are only between 1 and 7 substantiated fatalities caused by a centipede bite, dating back to 1932. The most well-documented case happened in the Philippines in 1932, where a seven year old female in the Philippines became severely ill and died shortly after she was bitten on the head by a S. subspinipes centipede.
To put this in perspective, you’re much more likely to be seriously injured by common household items than by a centipede bite. The question of if centipedes are dangerous has a pretty clear answer when you look at the actual data: they’re far less dangerous than many other things we encounter every day.
First Aid and Treatment for Centipede Bites
If you do get bitten by a centipede, here’s what you should do:
Immediate care:
- Wash the exposed area with plenty of soap and water. DO NOT use alcohol to wash the area
- Apply ice packs as the cold elevates the pain threshold, impedes nerve conduction, and vasoconstricts vessels to prevent tissue edema
- Apply the ice for 10 minutes, then remove for 10 minutes, and repeat as needed
Pain management:
- Take over-the-counter pain relievers like ibuprofen or acetaminophen
- Some patients report pain improvement with submersion of the extremity in hot water, as it is thought to denature any heat-labile toxins in the venom (though some people find this makes the pain worse)
When to see a doctor:
- If you develop signs of infection (increased redness, warmth, pus, red streaking)
- If you have an allergic reaction (difficulty breathing, widespread rash, dizziness)
- If symptoms don’t improve within 48 hours
- If the patient has no tetanus vaccination within the past 5 years, update tetanus vaccination
Most centipede bites heal completely on their own within a few days to a week.
Who Is Most at Risk from Centipede Bites
While centipede bites aren’t usually serious for healthy adults, some people are at higher risk for complications. The majority of bites are not life-threatening to humans and present the greatest risk to children and those who develop allergic reactions.
Higher risk groups include:
- Young children, whose smaller body size means venom affects them more
- People with compromised immune systems
- Those with known allergies to insect venom
- Anyone with heart conditions (since some centipede venoms can affect the cardiovascular system)
Bites can be dangerous to small children and those with allergies to bee stings. The venomous bite of larger centipedes can induce anaphylactic shock in such people. If someone in these high-risk groups gets bitten, it’s worth getting medical attention even if the symptoms seem mild at first.
Are Centipedes Dangerous to Pets
Pet owners often worry about whether their furry friends are safe around centipedes. The good news is that most pets handle centipede encounters just fine. Besides a little discomfort, most dogs are unaffected by eating centipedes or receiving a bite.
Cats are natural hunters and might try to catch centipedes they see running around the house. When cats see centipedes dashing about, they may give chase. These clashes take place in kitchens, bathrooms, and basements. Centipede bites do not cause any known health issues for cats.
However, just like with humans, very small pets or those with health issues might be more sensitive to centipede venom. If your pet gets bitten and shows signs of distress, difficulty breathing, or excessive swelling, it’s worth calling your vet.
The main risk is actually the opposite: your pets are more likely to harm the centipede than the other way around!
How to Prevent Centipede Encounters
The best way to avoid having to worry about whether centipedes are dangerous is to prevent them from getting into your home in the first place. Centipedes need three things to thrive: moisture, food (other insects), and hiding places.
Reduce moisture:
- Repair water leaks, use dehumidifiers to keep basements dry and run exhaust fans in bathrooms and attics to help eliminate excess moisture
- Fix any plumbing leaks promptly
- Improve ventilation in damp areas
Seal entry points:
- Seal holes, cracks and gaps around the outside of your house to keep centipedes and other insect pests from getting inside
- Use caulk around windows, doors, and baseboards
- Install door sweeps and repair torn screens
Remove hiding spots:
- Reducing clutter in basements, crawl spaces and attics will limit a centipede’s options for hiding places
- Keep firewood away from the house
- Clear leaf litter and debris from around your foundation
Control other pests: Since centipedes hunt other insects, getting rid of their food source will make your home less attractive to them. Regular pest control can help eliminate the spiders, cockroaches, and other bugs that centipedes like to eat.
The Bottom Line on Centipede Safety
So, are centipedes dangerous? For the vast majority of people, the answer is no. While any centipede bite can be painful and unpleasant, serious medical problems are extremely rare. Most encounters result in nothing more than temporary pain and swelling that goes away on its own.
The key points to remember:
- Most centipede species can’t even break human skin
- Even the largest, most venomous centipedes rarely cause life-threatening injuries
- Deaths from centipede bites are extraordinarily rare
- Simple prevention methods can keep centipedes out of your home
- Quick first aid can manage most bite symptoms effectively
The bottom line is that while you should treat centipedes with respect and avoid handling them, there’s no need to panic if you encounter one. Focus on prevention, know basic first aid, and remember that these ancient predators are generally much more afraid of you than you are of them.
If you have a centipede problem in your home, it’s usually a sign that you have other pest issues that need addressing. Taking care of moisture problems and sealing entry points will go a long way toward keeping both centipedes and their prey out of your living space.
