TD Problem

[thejai]

I'm making a td where the players can maze. The monsters have an attack and will attack if they block. One thing that goes wrong is that the monsters attack even if the person isn't blocking. It's the collision between the other creeps, but I already set their collision to 0 and the tower's collision to 0. After that is done they still attack if it's too clogged. Can someone please help me find a way to prevent unnecessary attacking of towers?