Today we are going to re-organize the main behavior tree used by NPC AI characters in combat and other decision making process. Here, we will create sub behaviors trees for different cohesive behaviors and use the in a main behavior tree. For example, we will create a separate behavior trees for combat part, search last seen location, search noise location and regular duty parts of the main behavior tree and incorporate them as sub behavior trees into the main tree. This will make it easier for us to organize the behavior tree and increase clarity of what's going on in AI decision making process.