The creepy, crawly bugs with seemingly hundreds of legs in your basement might look similar at first glance.
If you don’t know what to look for, you might think that millipedes and centipedes are the same.
Are millipedes and centipedes the same? Millipedes and centipedes are not the same. Millipedes are cylindrical and have two sets of legs positioned under the body per segment. Centipedes are flat and have one leg pair on the sides of the body per segment. Diet, habitat, and defense differ as well.
Don’t feel bad if you assumed that these two creatures were one and the same. Lots of people routinely make the same mistake.
As you learn more about how incredibly different they actually are, you may discover that you find them more fascinating than creepy.
How Are Millipedes and Centipedes Similar?
Millipedes and centipedes are essentially cousins in the animal kingdom. They are part of the segmented arthropod family.
They are also classified as myriapoda, which literally means “10,000 legs,” though no millipede or centipede has ever been recorded with that many.
The longest millipede has up to 750 legs, while centipedes can have up to 350.
You can find millipedes and centipedes on every continent except Antarctica.
They breathe through spiracles and have poor vision, relying instead on vibrations in their numerous feet to determine their surroundings.
Scientists estimate that there are at least 8,000 species of centipedes and at least 80,000 species of millipedes.
How Are Millipedes and Centipedes Different?
Millipedes and centipedes have very different diets.
Millipedes are detritivores, which means they eat dying or decomposing organic material.
Some examples of this include mulched flower beds, damp soil, compost piles, garbage, sheds, manure, piles of cut grass, and fallen leaves.
If you’ve ever lifted rotting bark off of a log, you’ve probably seen a number of millipedes scamper for cover.
Eating and digesting decomposing plant matter like fallen trees makes millipedes incredibly beneficial to the soil and a critical part of the ecosystem.
Centipedes, on the other hand, are carnivores. This means that they eat other living animals. Specifically, centipedes eat spiders, insects, and smaller arthropods.
They kill their prey by using the maxillipeds (appendages on the first or first three segments) to hold onto the prey before injecting it with venom.
Centipedes have larger, stronger jaws than millipedes for this purpose.
Like millipedes, centipedes can be helpful in gardens and lawns because they help control the populations of pests that might be harmful to living plants.
Because centipedes are carnivores, they are aggressive enough to fight back against their predators. In this case, their maxillipeds are used for defense to overtake the attacker.
A millipede does not have the organs necessary to bite and spread venom, so they must secrete a liquid, cyanide-like venom to discourage predators.
When attacked, they also curl up into a spiral ball, using their hard exoskeleton to protect themselves.
Millipedes are slower and built more for burrowing, while centipedes are quick and run away from potential attackers.
Though similarly shaped, there are key differences in the way centipedes and millipedes are built.
Centipedes are flat and more flexible, allowing them to move more quickly.
Millipedes are almost completely cylindrical and are rigid, allowing them to burrow quickly and efficiently.
Their body type, however, makes them poor swimmers, and you’ll often find them dead in swimming pools.
Are millipedes capable of swimming at all? Find the answer here.
Centipedes have only one pair of legs per segment, while millipedes have two pairs of legs per segment, except for the first four segments.
The centipede’s last pair of legs extend straight backward and are not used for locomotion, while the millipede’s last legs are parallel with the rest of the legs and are used to move.
Millipede antennae are shorter than that of a centipede, which helps the centipede as a predator.
Centipede legs are longer and point away from the body, while millipede legs are shorter and point toward the ground.
Centipedes are able to live in dryer environments because they have a waxy layer of exoskeleton that retains moisture.
You can find centipedes in most types of climates, including desert, arid climates.
Millipedes live exclusively in more humid environments and do not have a waxy layer of the exoskeleton.
Millipedes burrow and can be found underground consuming decaying plant material.
Getting Rid of Millipedes and Centipedes Without Chemicals
When attempting to prevent millipedes and centipedes from infesting your home, it is important to remember what attracts them.
As a general rule, millipedes are in search of moisture or dryness (if their environment has become too saturated) while centipedes are in search of prey.
Make it difficult for millipedes to enter your basement or crawlspace by keeping their favored dwellings away from your home.
- Replace existing mulch around flower beds and perimeter gardens with pea gravel or pebbles.
- Rake leaves before they begin to decompose in the yard, and dispose of them as soon as possible.
- Attach extensions to existing gutter drainpipes to direct water farther away from the house.
- Use a dehumidifier to dry out all damp areas in the home, especially basements.
- Replace all damaged weather stripping on exterior doorways. This will help seal the millipedes out of the house.
Remember that millipedes are seeking humid, dark places, so focus your efforts on these areas.
For centipedes, work to keep prey, such as spiders, insects, and other arthropods, out of your home.
This will keep centipedes from wanting to enter and will starve them if they do.
Additionally, try to keep their habitat away from the foundation of the house.
- Keep centipedes’ prey (cockroaches, flies, silverfish, spiders, other arthropods, etc.) out of the house.
- Remove centipede habitats from near the foundation. These would include garbage, rocks, boards, and compost piles, among other things.
- Seal and caulk all cracks and gaps in the foundation. Keep doors closed and make sure there is appropriate weather stripping in all doorways.
- Though centipedes can live in dry environments, most household varieties prefer moisture. Try to keep crawlspaces and basements as dry as possible.
If you’ve lost the first round of the battle and need to remove these bugs from your house, you should know that they are not entirely safe to touch.
Instead, use a broom or vacuum cleaner to suck up the bugs. Gloves aren’t a bad idea either.
If these solutions are impossible or impractical, or if they have failed to solve the problem, there are pesticide options to consider.
Always obey all safety warnings and instructions on the pesticide container, and keep the chemicals away from children.
If you’ve located the area in which the millipedes or centipedes are entering your home, apply a home-safe pesticide to that location.
Window perimeters, doorframes, crawlspace vents, and utility openings should be treated as well.
Ortho Home Defense is a long-lasting bug barrier that will kill both millipedes and centipedes and provides three months of additional protection after application.
Be sure to read through our top pesticide recommendations for millipedes, as they will work for centipede eradication as well.
Are Millipedes and Centipedes Dangerous to Humans?
Millipedes are docile and non-aggressive.
When threatened, they secrete a cyanide-like substance that can cause minor irritation on human skin and in eyes (some tropical species of millipedes can cause much more serious irritation).
Although they are not particularly dangerous, many people want nothing to do with them and are eager to eliminate as soon as they’ve been spotted.
As with most pests, prevention should always be your first plan of attack.
In our Guide to Getting Rid of Millipedes, we tell you how to effectively keep them out of your home and provide elimination methods should they be needed.
A centipede bite can kill small prey but typically is not life threatening to humans. It might be able to puncture human skin, however.
Depending upon the size of the centipede, their bite might cause irritation similar to a bee sting.
There are some species of centipedes, however, that are dangerous to humans.
Amazonian giant centipedes, which can be found in South America, are aggressive and can grow up to 1 foot in length.
The Texas redheaded centipede is found in Texas and can grow up to 8 inches in length. Both of these can cause major irritation and illness with their bite.
Millipedes and centipedes might appear to be similar in some areas but are actually unique creatures.
Though they are related segmented arthropods, they differ in number and placement of legs.
Their diets are vastly different, as centipedes are carnivorous and millipedes are detritivorous.
Though they are different bugs, the necessary steps to prevent them from entering your home are similar.
Remove the things that attract them (moisture for millipedes and prey for centipedes) and make it difficult for them to enter by moving their habitats away from your house.
Need more information on dealing with millipedes? We have a variety of articles full of information on prevention and elimination.