Zoology

Animal classification, locomotion, metabolic scaling, and navigation

What is zoology?

Zoology is the study of animals — their classification, behavior, physical structure, and how they've adapted to the enormous variety of environments found on Earth, from the deep ocean to the driest deserts.

Classifying the animal kingdom

Animals are grouped into major categories based on shared body plans and characteristics. Vertebrates (animals with a backbone) include fish, amphibians, reptiles, birds, and mammals. Invertebrates (animals without a backbone) are far more numerous and diverse, including insects, spiders, mollusks, and worms — in fact, the vast majority of all known animal species are invertebrates, even though vertebrates tend to receive more attention.

Animal body plans

Different animal groups are built around fundamentally different body plans. Insects and other arthropods have a hard external skeleton (an exoskeleton) and jointed limbs. Mammals and other vertebrates have an internal skeleton that grows along with the body. Mollusks like snails and octopuses have a soft body, sometimes protected by a hard shell. These different body plans come with different advantages and constraints, shaping how each group moves, grows, and survives.

Animal behavior

Zoology also studies how and why animals behave the way they do — feeding strategies, mating behavior, communication, migration, and social organization. Some behaviors are largely instinctive (present from birth without needing to be learned), while others are learned through experience or observation of other members of the same species.

Why zoology matters

Zoology underlies wildlife conservation efforts, veterinary medicine, animal agriculture, and pest control, and it provides essential comparative context for understanding human biology, since many animal species are studied specifically because they share biological mechanisms with humans.