Lesson 8

1. Lesson 8 Living on Land: Millipedes

2. Overview • Review the necessary elements of a habitat for millipedes. • Create habitat for the millipedes. • Record the living and nonliving elements in the habitat. • Observe the millipedes and record questions about them.

3. Background • Millipedes are arthropods. • There are around 7,500 known species of millipedes. • Cold blooded

4. Body Structure and Function • Vary in size and shape. • The longest ones in the U.S. are found in California and are about 6 ½ inches. • Millipedes found in the U.S. live in woodland as well as desert environments. • Long segmented body • Round head with a pair of antennae • Two pairs of legs attached to most body segments • Strong internal jaws • Exoskeleton – hard shell

6. Body Structure Continued • Vary in color. • Many are black or brown, but some are vividly colored. • Its many legs, ranging from about 18 to 750, help it push slowly forward by touching the ground in various stages. • The word millipede means “thousand footed,” but no millipede has that many feet. • As a millipede walks, it frequently taps the surface with it antennae, which have hairs for feeling, smelling, and tasting. • Its strong jaws enable it to chew plant material. • To burrow into the ground, the millipede lowers its head and pushes straight ahead.

8. Body Structure Continued • Millipedes typically avoid light. • Some are blind. • Our millipedes have a cluster of simple eyes on each side of the head that are sensitive to light but do not actually see. • The majority of millipedes live in dark, damp places: under stones, soil, or decaying material such as leaves, logs, and stumps. • Millipedes benefit gardens by eating decaying plant material, which helps to recycle the minerals in soil.

11. Protection • When disturbed, some millipedes “play dead.” • Longer ones coil up to protect their soft underside. • Because they are slow moving animals, most millipedes developed another defense mechanism: a row of “ stink glands” along each side of the body. • These glands produce a bad smelling substance that can deter predators. • To humans, however, millipedes are quite harmless.

13. Life Cycle • Female millipedes lay their eggs in the soil. • When they hatch, the young usually have only three pairs of legs. • The number of segments and legs increases each time the millipede grows and molts. • The millipede’s growth pattern is called incomplete metamorphosis because there are only 3 life stages: egg, young (nymph), and adult. • A complete metamorphosis usually contains 7 immature stages. • Millipedes may live for several years.

15. Elements for their Habitat • Water/moisture – spray bottle • Space – so can crawl • Plants, bark, twigs, and rocks in habitat • Food – leaf litter, mushroom, lettuce, orange, apple (remove old food before putting in new so not get mold) • Land – soil and gravel • Light– indirect light through windows (dim light is preferred) • Air – tape the dial so have a small hole to allow air in, but does not allow the millipede to crawl out

16. Observation • What happened when you put food in the habitat? • Do the millipedes respond to food the same way the frogs and crabs do? • In what ways is the millipede’s response different? • What happens when you shine a flashlight on the millipede? • What happens if you gently touch the millipede with your pencil? • Were the millipedes at the top of the surface, under a piece of debris, or buried in the soil?

17. The End!!!