Small invertebrates are animals without a backbone that are typically less than a few centimeters in size. They include groups like insects, spiders, worms, and crustaceans. These creatures can be found in various environments, from soil and freshwater to oceans, playing essential roles in ecosystems as decomposers, prey, and pollinators. Despite their small size, small invertebrates are incredibly diverse, with millions of species identified. They exhibit a wide range of adaptations, such as camouflage and bioluminescence, which help them survive in their habitats. Their presence is crucial for maintaining ecological balance and supporting larger animals in the food chain.