Arachnida is a class of invertebrates with jointed-legs, most have eight legs, but some have front legs that have converted to a sensory function or appendages that appear to be legs. The legs serve various purposes, such as feeding, defense, and perceiving the Arachnida’s surroundings. Almost all arachnids are terrestrial, although some live in freshwater and marine environments. Spiders are the largest order in the class, but mites, ticks, and scorpions are also members of this class. The term, Arachnida, comes from Greek mythology when a prideful human weaver named Arachne was turned into a spider.
Arachnids have 8 legs, 2 main body segments, no wings or antennae, and are not able to chew. In some species arachnids can grow extra appendages that can look like extra legs. They often get confused with insects, but insects only have 6 legs.
Most species of arachnids can only eat food in a liquid form and not in solids. They do so by squirting digestive chemicals into their prey and then sucking out the body juices. Arachnids typically eat insects and other invertebrates. Mites are the only arachnids who consume a wider variety of food like fungus, plants, dead animals, bacteria, and other invertebrates.
Arachnids have 8 legs while insects have 6. Arachnid bodies are divided into 2 parts, the cephalothorax and abdomen and insect bodies are divided into 3, the head, thorax, and abdomen. Arachnids do not have an antennae nor wings, while all insects have antennae and some also have wings. Insects belong to the Insect class and arachnids to the Arachnida class.