A Look at Spiders and Their Kin Chelicerates include some marine species such as horseshoe crabs and more familiar arachnids. Arachnids include spiders, scorpions, ticks, and mites. Spiders are keen predators that trap insects in their webs produced as silk strands from the abdomen. These are important components of food webs and serve as human food also. Millipedes and centipedes have long, segmented bodies with many legs.
Millipedes are cylindrical, slow-moving vegetarians.
Centipedes have a more flattened body, move rapidly, and prey on small invertebrates using their fangs and venom glands. A Look at Insect Diversity Insects display many adaptations. Unique Malpighian tubules process metabolic waste and aid in water retention. Insects display enormous diversity. Their great success is due to their ability to exploit nature's resources during different stages of metamorphosis, such as larvae, nymphs, and pupae.