The Dink Network

The last bit (fixing brains and go back to business, get_next_sprite_with_this_brain) is probably finding ducks feeding from the other piles and they won't get changed back because they're not targeting the right pile.
Check for inside_box again before you check the targeting and see if that works.

I like the idea!

Edit: I notice an sp_gold check, but it's not set anywhere. Is that part of it?
Also, with my idea (presuming it works) you might still have problems if the piles are near each other. Maybe set sp_gold for the ducks eating from this pile? 1 for first pile, 2 for 2nd etc. Perhaps over-complicated...