roles (which can include experts as well as organisational roles)
a collective such as a team
an individual (rarely)
We typically associate Agency with human beings, i.e, Actors
Actants indirectly let us map Agency at a much subtler level
Examples
Social network (e.g. Facebook)
According to actor-network theory, the technological activities — computers, and phones — have the same amount of agency, and are as important to the network, as the people and the communication they support