Instinct is a term used to describe a set of behaviours that are both unlearned and set in motion as the result of some environmental trigger. Instincts are also often discussed in relation to motivation since they can also occur in response to an organism's need to satisfy some innate internal drive tied to survival. Instincts are present across species and are consistent within individual species. In other words, many different species rely on instincts, and if one member of a species possesses an instinct, then they all do. Before we move into a discussion of specific types of instincts, it is important to distinguish the difference between instinct and a reflex. Both are types of unlearned behaviour that tend to serve a survival purpose. The difference is that a reflex is typically a simple reaction or a response, whereas instinct is a much more complex set of behaviours.