Sarah and Emma finished their science curriculum a few weeks ago.  We didn't want to stop learning just because we completed the book, so we began a unit study on snails and slugs. 

We learned about their classification.  Kindom~ Animal:  They are in the largest part of this group, the invertebrates which means they have no hard exo-skeleton.  Within the invertebrate category, snails and slugs are grouped with the mullusks.  Phyllum~ Mollusca:  Mullusks are soft bodied animals without internal skeletons.  Many have shells and a muscular foot.  Class~ Gastropoda:  Gastropod comes from the Greek, "gastros" meaning stomach, and "podos" meaning foot.  There are approximately 80,000 gastropods in the world. Some live in the sea and breathe with gills; others on land or in ponds breathing with lungs.  Order~ Pulmonata:  Pulmonates are snails and slugs that live on land or in fresh water and breathe with lungs. 

We learned that there are land snails (garden snails) and pond snails.  Land snails have two pairs of tentacles.  They withdraw into their shells when water is scarce and become dormant.  They can live 5-10 years.  Pond snails have one pair of tentacles.  Some have gills, others have lungs. 

Slugs look like snails without a shell.  They live only about a year and are slow in developing.  Like snails, they need moisture to survive, and are nocturnal. 

Pulmonates need moisture; without it they will shrivel up and die.  They eat dead leaves and debris that falls to the ground.  In ponds, they eat algae, decomposed plants, and even other animals. 

The reason some pulmonates live on land is because they can create their own moisture to survive; slime!  One of the biggest dangers is drying out.  The slimy mucous they create keeps their bodies moist and helps them move across different types of terrain. 

We also learned that however interesting snails and slugs may be, they are the enemies of the garden.  They chew plants down in layers leaving brown holes in the vegetation.  Their favorite meals are young seedlings and transplants.  The best way to rid your garden is through organic means.  You can use iron phosphate which will cause the critters to stop feeding and die within 3-6 days.  You can also sprinkle salt on the slugs which will draw out their moisture.  A sprinkling of coal or wood ash around plants will make it difficult for the animals to get to the plants.  This will also cause their bodies to dry out if they try crossing the line. 

Snails and slugs have many predators.  Humans, beetles, toads, snakes, and turtles are all a danger to the snail. 

Snail shells: Their shells are used to protect their soft bodies.  The shells are made of calcium and grow as the snail grows.  If the shell cracks, the animal can repair it.  They do not change shells.  Most shells open to the right while few open to the left.  Most are colored yellows, browns, or greens.  If you look closely at the whorls of the shell, you can see the lines of growth!

This was a really cool unit and we loved learning about these creatures.  We are now putting our lapbooks together.  So far the girls are decorating the outside of their lapbooks.  I'll take pictures of the finished product!