Elements of Behavior
Behavior is what animals do. It can be defined more precisely as an internally directed system of adaptive activities that facilitate survival and reproduction. Ethology is the scientific study of animal behavior — particularly when that behavior occurs in the context of an animal’s natural environment. Ethologists strive to observe, record, and analyze each species’ behavioral repertoire in order to understand the roles of development, ecology, physiology, and evolution in shaping that behavior. Insects have always been popular as subjects for behavioral research because, in comparison to vertebrates, they have relatively simple nervous systems, they exhibit discrete responses to external stimuli, and they are more conducive to ethical experimentation. Although they may lack the capacity for intelligence or forethought, they still display a fascinating array of adaptive behavior that is a source of wonder and amazement to anyone who takes the time to study it.
Any behavior we can observe by watching an animal is overt behavior. In insects, this usually includes responses to external stimuli as well as spontaneous activities that are related to the animal’s internal (physiological) needs. Ethologists use the term “drive” (“hunger drive”, “sex drive”, etc.) to describe motivational urges that compel animals to behave as they do. Insects also appear to have internal “drives” for dispersal or migration as well as “drives” to complete stages in development such as constructing a nest or spinning a cocoon.
In general, overt behavior may be classified as innate, learned, or complex. Many people use the term “instinctive behavior” as a synonym for innate behavior. Although both terms refer to natural, inborn patterns of behavior, some ethologists avoid the word “instinct” because in common English usage it often includes the connotation of acquired aptitudes or talents, as in: “She has good business instincts.” Purists avoid any confusion in meaning by using the adjective “innate” for behaviors that are acquired through inheritance, and “learned” for behaviors that are acquired through experience. Complex behavior is a blend of innate and learned components.