WORMS “EWW, AAH, ICK” SCIENCE EXPLORATIONS

WORMS Making science fun is essential. Kids learn more when they are having fun. Teaching is more enjoyable when the kids are having fun. Fun is good. Worms are fun. Try it!

What can you teach with worms? Ecosystems Food chains and webs Life cycles Adaptations How the earth changes Decomposition Qualitative and quantitative data collection Inquiry  Teacher guided  Student guided

I LOVE WORMS! Worms require much less daily care than typical class specimens and they provide endless opportunities for learning about cycles, systems, decomposition, food, soil, science inquiry, and basic ecological connections.

Darwin declared that no other animal has “played so important a part in the history of the world, as have these lowly organized creatures.” Children love digging into the world of earthworms and it is a remarkably fun way to teach scientific inquiry. You must be prepared to get down and dirty if you really want to dig into an intriguing annelid investigation.

Oligochaetology Kingdom: Animalia Phylum: Annelida Class: Oligochaeta Segmented worms make up the Phylum Annelida. The phylum includes earthworms and their relatives, leeches, and a large number of mostly marine worms known as polychaetes. Annelids can be told by their segmented bodies. Polychaetes (meaning "many bristles") have, predictably, many bristles on the body, while earthworms and leeches have fewer bristles. There are about 9000 species of annelid known today. Eisenia fetida and Lumbricus rubellus Classification of earthworms is confusing. These two worms are commonly named redworms or red wigglers. They are both good composting worms.

Anatomy/Physiology Worms are cold-blooded invertebrates. They can live in cold temperatures by hibernating or burrowing deeper into soil Worms have no eyes, but can sense light and feel vibrations in the ground. They have no lungs. They breathe through their skin. Worms come to the surface when it rains to find food, not because they're drowning! A healthy worm can eat up to 1/3 of its body weight in one day.

The saddle like bump in the middle of the worm is called the clitellum. A worm’s body is covered in mucus. This helps with respiration. Worms also secrete mucus to form cocoons for babies and as a defense mechanism. Mucus also helps line the tunnels they make so the dirt doesn't collapse on them. Worms move by using the setae (bristles) on their bodies, which act as little arms helping them push forward. If you cut an earthworm in half you don't get two earthworms. Only the front end will survive and will re-grow a tail end. Earthworms vary in size.

Eating What do earthworms eat? The remains of living things that are in the soil. Worms are decomposers = eaters of decaying material. They enjoy leaves and roots, kitchen leftovers and sometimes decomposing animals. Worms also eat living organisms (bacteria, fungus, etc). How do earthworms eat? They don't have teeth but have very strong mouth muscles They eat small pieces of food at a time. They also "swallow" soil as they burrow and extract nutrients from it.

Earthworm Ecology Increase pores in the soil (deeper and faster penetration of water and oxygen)= "open up soil." Tunnel deeply in the soil and bring deeper soil closer to the surface, mixing it with the topsoil. Slime, a secretion of earthworms, contains nitrogen, an important nutrient for plants. Earthworm poop = "casts". Makes soil more fertile. It contains concentrated nitrate, phosphorous, exchangeable magnesium, potassium and calcium -these = plant nutrients, help regulate soil pH. Can be used for composting to break down food waste, yard waste, to create gardening soil. Food for others. What eats them? Snakes, birds, moles, toads, foxes, beetles, centipedes, leeches, slugs and flatworms.

Factors to consider when designing or guiding worm investigations: Light vs dark: Even though worms don’t have eyes, they can sense light, especially at their anterior (front end). They move away from light and will become paralyzed if exposed to light for too long (approximately one hour). Wet vs Dry: If a worm’s skin dries out, it will die (breathes through skin= requires moist skin). Also it is easier for worms to move in wet environments. Worms can drown. Cold vs Warm: Worms can freeze. They are cold-blooded.

WORMS Making science fun is essential. Kids learn more when they are having fun. Teaching is more enjoyable when the kids are having fun. Fun is good. Worms are fun. Try it!