This set of scripts is designed to let you create "swarms" of instances and have them behave in an appropriate manner. This is not an accurate depiction of swarm behaviour and contains nothing for instance avoidance within the swarm itself, but it is rather a "cheap" effect to simulate a swarm of instances. As such it works well and still looks "realistic" even though it's not.
The scripts are pre-prepared to permit you to tweak a great number of baseline characteristics, like how fast the swarm instances should move, turn, change target, etc... and you can also have them attack (shoot) specific target instances, giving range, spread, etc...
All scripts are clearly commented and the asset comes with a basic demo of how they should be used. You can find a live demo here: https://dl.dropboxusercontent.com/u/47471635/Marketplace%20Demos/SwarmDemo.html
NOTE: WebGL is required for the live demo!