While this field is advancing rapidly, and sophisticated approaches are being constantly developed, for those who want a gentle introduction, I venture to recommend our book: https://www.amazon.com/Biological-Computation-Chapman-Mathem...

Section 6.1 deals with swarm intelligence (ant colony optimization, cemetery organization, particle swarm optimization). 6.2 is on artificial immune systems.

A more biological+philosophical exploration on issues of collectivity will be found in the following book, which is already available for pre-order on Amazon, I see:

https://www.amazon.com/Landscapes-Collectivity-Sciences-Theo...