How to specify collisions between different objects

I have a clump of cubes that spawn when an enemy is killed and they move towards the player and destroy whenever they collide with him. I want to be able to have them not collide with the map or other enemies because i find that it has odd reactions when it does but i need them to collide with each other so that when they spawn in they explode outward… Is what im trying to do possible? Im trying to imagine a way to make a collider react with some objects and not others without having to change the properties of the other objects and i cant think of any solution.

You can do just that using physics layers, check out the manual page here