The habitats of arthropods range from the polar regions, to urban areas (including parks, gardens and buildings), temperate and coniferous forests, tropical forests and rain forests, and deserts and semi-deserts. Arthropods are also found in open habitats, such as savannas, grassland and scrubland.

Arthropods can also be found in wetlands, lakes, ponds, marshes, swamps and bogs. The larvae of some arthropods live in flowing water, such as rivers and streams. They can be found in the seas and oceans. Some are parasitic and live on or within other animals. This ability to adapt to a great variety of habitats has made arthropods one of the most successful groups of animals on earth.

Among the arthropods that live in the seas and oceans are crustaceans, such as lobsters, crab, shrimp and their relatives. This group contains the world's largest arthropod, the Japanese spider crab. This animal can grow to 12 feet long and can live a century or more.

Scorpions are at home in the desert. They are an ancient group of arthropod, and bear pedipalps that resemble claws and curved tails that have a stinger at the end.

Blackflies are found near water and can also be found in the Arctic region. Swarms of them torment hosts, including cattle and humans. Fleas are arthropods that exist as external parasites on mammalian hosts.