Entognatha is a group of small, wingless arthropods that includes three main orders: Collembola (springtails), Protura, and Diplura. These creatures are characterized by their internal mouthparts, which distinguishes them from other arthropods. They are typically found in soil, leaf litter, and decaying organic matter, playing a crucial role in nutrient cycling. Entognatha species are generally less than a few millimeters in size and have a simple body structure. They are important for soil health, as they help decompose organic material and aerate the soil. Their presence indicates a healthy ecosystem, making them valuable for ecological studies.