Invertebrates are animals that do not have a backbone or spine. They make up about 95% of all animal species on Earth, including creatures like insects, spiders, crabs, and jellyfish. These animals can be found in various habitats, from oceans to forests, and they play essential roles in ecosystems, such as pollination and decomposition. Despite their lack of a backbone, invertebrates exhibit a wide range of shapes and sizes. Some, like octopuses, are highly intelligent and can solve problems, while others, like earthworms, help enrich the soil. Their diversity and adaptability make them fascinating and vital to our planet's health.