  Terms such as leader, mediator, and follower sound equal in the description
of a pack of wolves, a street protest crowd, or a business team and have very
similar meanings. This indicates the presence of some general law or structure
that governs collective behaviour. To reveal this, we selected the most common
parameter for most levels of the organisation -- motion. A causality analysis
of distance correlations was performed to obtain follow-up networks that show
who follows whom and how strongly. These networks characterise an observed
system in general and work as an automation bridge between the biological
experiment and the broad field of network analysis. The proposed method was
tested on 3D image data from a controlled experiment on a 6-member school of
aquarium fish of Tiger Barb. The network patterns can be easily ethologically
interpreted and agreed with expected behaviour.
