Arthropoda (Crustaceans/Insects)

Family: Arthropoda
This phylum is divided into 4 parts. They are known as Crustacea, Myriapoda, Arachnida, and Insecta. They are made up of crustaceans like crabs, lobsters, shrimps, barnacles, woodlice, or insects like cockroaches, spiders, or dragonflies. They are all related because first, they are invertebrates, so they have an exoskeleton. They also have a segmented body with jointed appendages or legs. Some insects have a cephalothorax (the fused head and body of spiders and other chelicerate arthropods).

Crustacea
These are invertebrates that hide under a bulky or thin exoskeleton like crabs or shrimp. They can have up to five legs or more, and mostly live in water. Crustaceans have two antennas and wings are absent. For their body composition, they have an infused head within the thorax (body), and projects a short tail. They can range from plankton-sized creatures such as water fleas to more familiar animals like crabs and lobsters.

Myriapoda
These are a diverse species of centipedes, millipedes, and insects related to Myriapoda. They have up to thousands of legs, two antennas, and no wings. All myriapods are in terrestrial forms, and can be found in humid environments such as soil, leaf litters, or under stones or wood. Having a secure shelter is one essential equipment, but also a stinky defense. Many species of myriapods possess repugnatorial glands, which are specialized glands that secrete foul-tasting compounds and thus function in defense againt predators.

Arachnid
These are scorpions, king crabs, spiders, mites, ticks, etc. They can have up to more than 4 appendages and no antennas. They can live in either terrestrial or aquatic biomes. Spiders live in habitats where smaller insects are likely to be preyed upon. Mites and ticks are parasites so they live in moist and humid environments, particularly in or near wooded or grassy areas. Scorpions live in a variety of biomes, but prefer desert or semi-arid areas. King crabs live in cold aquatic waters.

Insecta
Insects have three main body parts which are the head, thorax, and abdomen. In addition, there are two antennas above its compound eyes. On the thorax, or the body, some have wings while others don't. 6 or more legs extend from the thorax, which are actually three pairs of legs. And the wings may have usually four or two pairs.