Once the agents are defined, agent behaviors are specified. One needs to have a theory of agent behavior as a basis for modeling agent behavior.For example, a normative model in which agents attempt to optimize a well-defined objective can be a useful starting point to eventually developing more descriptive and domain-specific behavioral heuristics. Alternatively, one may begin with a generic behavioral heuristic, such as anchoring and adjustment, to describe agent behavior or more broadly a formal behavioral modeling framework such as BDI (Belief-Desire-Intent) or others (Rao and Georgeff 1991). Ref: https://ieeexplore.ieee.org/abstract/document/5429318
Agents and environment can possess rules that will affect their behaviour and relationships with other agents and/or agents their surrounding environment. One rule-set can be applied to all agents or each agent (or categories of agents) can have its own unique rule set. Rules are typically based around ‘if-else’ statements with agents carrying out an action once a specified condition has been satisfied. However, rules can also be put into action in ignorance of the actions of other agents. Agents can also be imbedded with a notion of learning and thus ‘intelligence’ through evolutionary computation.
Agents can interact with each other and amongst themselves and with the environment. Relationships may be specified in a variety of ways, from simply reactive (i.e. agents only perform actions when triggered to do so by some external stimulus e.g. actions of another agent) to goal-directed (i.e. seeking a particular goal). The behaviour of agents can be scheduled to take place synchronously (i.e. every agent performs actions at each discrete time step, all change occurs simultaneously), or asynchronously (i.e. agent actions are scheduled by the actions of other agents, and/or with reference to a clock).