Ethology

Ethology (from Greek: ήθος, ethos, "custom"; and λόγος, logos, "knowledge") is the scientific study of animal behavior, and a branch of zoology (not be confused with ethnology).
Although many naturalists have studied aspects of animal behavior through the centuries, the modern science of ethology is usually considered to have arisen as a discrete discipline with the work in the 1920s of Dutch biologist Nikolaas Tinbergen and Austrian biologist Konrad Lorenz. Ethology is a combination of laboratory and field science, with strong ties to certain other disciplines — e.g., neuroanatomy, ecology, evolution. Ethologists are typically interested in a behavioral process rather than in a particular animal group and often study one type of behavior (e.g., aggression) in a number of unrelated animals.
The desire to understand the animal world has made ethology a rapidly growing field, and since the turn of the 21st century, many prior understandings related to diverse fields such as animal communication, personal symbolic name use, animal emotions, animal culture and learning, and even sexual conduct, long thought to be well understood, have been revolutionized, as have new fields such as neuroethology.

Etymology
The term "ethology" is derived from the Greek word "èthos" (ήθος), meaning "character". Other words derived from the Greek word "ethos" include "ethics" and "ethical". The term was first popularized in English by the American myrmecologist William Morton Wheeler in 1902. (An earlier, slightly different sense of the term was proposed by John Stuart Mill in his 1843 System of Logic. He recommended the development of a new science, "ethology," whose purpose would be the explanation of individual and national differences in character, on the basis of associationistic psychology. This use of the word was never adopted.)