Agents are basic Flora elements that respond to forces like gravity, attraction, repulsion, etc. They can also chase after other Agents, organize with other Agents in a flocking behavior, and steer away from obstacles.
Agents are highly configurable. For a complete list of options see the docs at http://www.florajs.com/docs/symbols/Agent.html
For an example of the Agent's seek behavior, set 'followMouse' to 'true' when creating the Agent.