By observing an organism over time, children can identify patterns in their observations, note growth or other changes, learn about the needs of the organism, and see how the organism creates the next generation of its species; all of these skills are science and engineering practices noted in "A Framework for K-12 Science Education"…

For farmers and gardeners, slugs and snails may be serious pests that will limit the amount of harvest, but for a child, they represent a world to be explored. To teachers, however, invertebrates are tools for broadening students' understanding about animals, the connections between animals and habitats or plants, and an engaging subject to write…