Centipedes and millipedes

Centipedes and millipedes are not insects because they have more than six legs. They are arthropods and are distant relatives of shrimp, lobster, and crayfish. Arthropods are an invertebrate animal with jointed legs and a segmented body with a horny casing (exoskeleton) that is shed periodically as the animal grows.  While their marine cousins live in the water, centipedes and millipedes are land dwellers. However, the centipedes and millipedes do prefer moist habitats. They are seen most often in the fall, and may move into homes during periods of heavy rain. The two creatures may look similar, but they can easily be identified if you know what to look for.

Millipedes have rounded bodies, while centipedes have flattened bodies. Another identifier is that millipides will curl into a spiral when threatened, and centipedes will not. Another way to tell them apart, and this one makes me laugh because how many people are going to get close enough to see this difference, is millipedes have two pairs of legs per body segment, while centipedes have only one pair of legs per body segment.

These arthropods can be found in humid or moist environments such as under logs, rocks, and moist decaying organic matter. The millipede feeds on decaying organic matter while centipedes feed on insects and other arthropods. Centipedes have a modified pair of claw-like legs behind their head. They can use this to inject venom into their prey.  However, they can rarely penetrate human skin, unless they happen to be a large species.  The bite from a large centipede can cause swelling and pain like what you would experience from a bee sting.  If you are allergic, it can be just as deadly as being allergic to bee stings. It is a good idea to never handle centipedes. Millipedes cannot bite, but they exude a stinky fluid that can be quite irritating to the skin of some people.

The chemical millipedes secrete is cyanide based. This chemical can kill many small species.  The chemical is only slightly irritating to human skin, but if you handle one you will notice a lingering odor on your hands.  Never touch your eyes after handling a millipede as the secretion is dangerous to the eye. After handling one, it is important to wash your hands with soap and water until the odor is gone. Interestingly, this substance is used by one species of monkey as an insecticide. The monkey bites into a millipede and rubs the secreted chemical all over its body and into its skin. This prevents fleas and mites from feeding on the monkey. There is one species of tunneling spider that is not afraid of the millipedes defense. The spider lies at the mouth of its tunnel, and when a millipede passes by, it grabs hold of it and injects its venom into the vulnerable under parts of the millipede before it can secrete anything to kill the spider.

Centipedes and millipedes do not carry diseases to man or to animals and plants, but they are undesirable in our homes.  When millipedes or centipedes are found in your home, there may be an underlying problem that needs to be corrected. Because both of these creatures prefer darkness and moist areas, they are often found in damp areas like closets, basements, and bathrooms.  If they are not in a moist area, they will eventually die due to desiccation, which is excessive loss of moisture in their bodies. If they are in moist areas they can survive a long time.

Removing organic debris or mulch from around your home can greatly reduce the chance of invading millipedes or centipedes. Piles of wood, too, should not be kept too close to your home. Over watering your gardens can result in a large millipede attack, but a natural balance of millipedes can be a good thing because they eat decaying matter. The centipede, too, can be an asset in the garden because it preys on pests and insects in the soil like slugs and fly pupae.  A safe and natural way to keep them from entering your home, other than the above mentioned ways, is to make a concoction of water and rosemary oil, sesame oil, or clove oil and spray or splash it around your home.

The centipede is a very interesting creature. Although they are called centipedes, they do not have 100 legs, which is what centipede means. They do have many legs with each leg being slightly longer than the one in front. Centipedes can have 15 to about 177 segments with that many legs. When they lose a leg, they regenerate (grow another one). They have a long antennae, and they breathe through spiracles, which are holes positioned along their body. There are some large centipedes in the West Indies that eat lizards and mice. This centipede, the Scoloendra gigas grows to be about 10 inches long. The centipedes enemies are shrews, toads, and in some countries humans eat them. (perhaps that is what gave that hiker the idea). There are at least 3,000 species of centipedes in the world. Some of these centipedes actually care for their eggs and the hatchlings.

The millipede is equally as interesting as the centipede. Their name, millipede, means a thousand legs. However, they do not have 1,000 legs. They have from 47 to 197 pairs of legs depending on the species.  Their first few segments have only one pair of legs, while the following segments have two pairs of legs. The second to the last segment has no legs, nor does the last anal segment have any legs. They have short antennae.  Millipedes, like centipedes, breathe through spiracles, holes positioned in pairs on the sides of their body. When they feel they are in danger, millipedes curl up into a spiral, which protects their very vulnerable and soft underside.  Millipedes have poor to no vision. There are about 7,500 species worldwide. Most of them are herbivores (plant-eaters), but a few are carnivores (meat-eaters).

There is one centipede that is quite capable of living in the house, and that is the house centipede (Scutigera coleoptrata). It is the only species that is capable of reproducing in houses. This centipede originally lived only in Mexico, but today it can be found throughout North America.  This centipede is seen at night when it actively seeks out its meal of insects. The house centipede is about 1 1/2 inches long and feeds on small insects such as cockroaches, clothes moths, house flies, and other insects.  The house centipede has very long back legs that it uses to capture its prey. It does this with an action like that of lassoing. This centipede is very beneficial to man, but most people would rather not have them in their homes.