Wikijunior:Bugs/Millipede

Rusty millipede (*Trigoniulus corallinus*)

What does it look like?

Have you ever been playing in a sandbox and seen a tiny critter with seemingly thousands of legs? Did it curl into a ball when you picked it up? You were holding a millipede. Millipedes are arthropods that have a large number of legs - two pairs of legs per segment. The name comes from the Latin roots milli ("thousand") and ped ("foot"). Millipedes do not have a thousand legs, although common species have between 80 and 400 legs (two or four pairs of legs per segment). Millipedes range in length from around 1.25 centimeters to 16.5 centimeters. Millipedes have very many short legs, which makes them rather slow. Millipedes, however, are powerful diggers! With their legs, they burrow underground, head first. Millipedes have flat, lensed eyes on the side or front of their heads. From birth, they gradually grow and add more legs at two pairs per segment.

Where does it live?

Most millipedes live underground. They have poor eyesight, because they don't need to see in the dark.

There are millipedes all over the world. The largest species is giant African millipede (Archispirostreptus gigas). One species of millipede( Pneumodesmus newmani) was the first known land creature! It lived around 428 million years ago, that's a long time!

What does it eat?

Millipedes are scavengers, and eat mostly dead vegetation. Most millipedes eat decaying leaves and other dead plant matter. They will eat anything from rotting leaves to apples, to potatoes! When eating, a millipede will moisten the food with secretions, and then scraping it in with the jaws.

How does it defend itself?

A millipede curled up in a defensive position.

When a millipede is in danger, it curls into a tight coil — protecting its delicate legs inside its armoured body. The millipede lacks the ability to bite or sting, so this is it's primary protection. Many species also put out poisonous liquid or gas through microscopic pores along the sides of their bodies. These poisons can burn ants and other insects that are attacking it. Any effects on humans are usually minor, but can cause skin irritation.

What stages of metamorphosis does it go through?

Most millipedes go through a simple stage of metamorphosis. During winter, adults keep safe and warm until spring. During spring, male and female millipedes become active and mate. Females will then lay eggs, covered in a sticky substance, in the soil. Larvae usually resemble small adults just days after hatching, and grow gradually in size. In other species, females do not lay eggs, but give birth to their young. Millipedes will take between 21 and 25 weeks to develop out of the basic stages, and grow for 2 to 5 years. After maturing, they will live for several more years.

The North American millipede Narceus americanus, with many pairs of legs.

What special behaviour does it exhibit?

The millipede burrows down into dirt in a wave-like pattern. It moves down a tunnel head first. While burrowing, millipedes seem to have the ability to restructure and secure the dirt around them. Millipedes also shed old exoskeletons as they grow larger.

How does this bug affect people?

Though it may seem small, the millipede is very important to the ecosystem! Since it is a scavenger, a millipede cleans up dead matter from the environment. The millipede is like a garbage man for the Earth! Occasionally, the millipede can be a pest as it eats plant stems or leaves. The creature may seem creepy with all those legs, but most won't do any harm at all. Be careful though, all those legs may tickle your skin!