I'll try to explain how the code work(I havent tried it yet)
-The player will leave crumbs as it moves, one at specified time.
-The follower will look for nearest crumb an go for it. This is the target_crumbs
-Once the follower reach the target_crumbs, the urrent crumb/target_crumb will be removed and it will look for another nearest crumbs.

Well, at least that what I though