If I have a group of entities all in the same area, how would I go about fixing the "crowding" problem so they don't overlap eachother when they are moving etc?

If I have a group of entities all in the same area, how would I go about fixing the "crowding" problem so they don't overlap eachother when they are moving etc?

i'd recommend reading up on RVO, they've demonstrated having thousands of entity's which can navigate an very crowded environment.