The field of study that focuses on animal life and behavior is zoology. Zoology is a major branch of biology concerned with animals—their structure, development, classification, evolution, habits, distribution, and relationships with ecosystems.
The word comes from the Greek zōion, meaning “animal,” and logia, meaning “study.” Aristotle is often considered an early founder of zoology because he systematically observed and described animal anatomy, reproduction, and behavior. The discipline became more formal during the Renaissance and expanded through the work of naturalists such as Carl Linnaeus and Charles Darwin.
Animal behavior is also studied within specialized fields. Ethology focuses specifically on behavior, especially under natural conditions, while behavioral ecology examines how behavior is shaped by environmental pressures and evolution. Zoology is the broader umbrella that includes these areas, along with anatomy, physiology, genetics, taxonomy, and paleozoology.
The other choices are narrower or concern different kingdoms: ichthyology studies fish, entomology studies insects, and botany studies plants. Zoologists today may investigate anything from whale communication and bird migration to animal diseases, conservation, and the effects of climate change on wildlife.