In the biological literature on animal behaviour, in addition to real exper
iments and field studies, also simulation experiments are a useful source o
f progress. Often specific mathematical modelling techniques are adopted an
d directly implemented in a programming language. Modelling more complex ag
ent behaviours is less adequate using the usually adopted mathematical mode
lling techniques. The literature on AI and Agent Technology offers more spe
cific methods to design and implement (also more complex) intelligent agent
s and agent societies on a conceptual level. One of these methods is the co
mpositional multi-agent system design method DESIRE. In this paper it is sh
own how (depending on the complexity of the required behaviour) a simulatio
n model for animal behaviour can be designed at a conceptual level in an ag
ent-based manner. Different models are shown for different types of behavio
ur, varying from purely reactive behaviour to pro-active, social and adapti
ve behaviour. The compositional design method for multi-agent systems DESIR
E and its software environment supports the conceptual and detailed design,
and execution of these models. A number of experiments reported in the lit
erature on animal behaviour have been simulated for different agent models.