The very nice setting gets the fourth star here. I could kind of tell from the initial set-up ... Spoiler what the solution would be. So I tapped the win as the bots came out to see which house B would choose. Then, guessing there was something more to it than a 1-tap win, tapped to pull B back and positioned him to herd the two Rs into the brick house. Confirmed my suspicions with a second attempt where B found the hidden zapper, as I suspected he might.
What a great level, the hidden aspect made the level much more challenging and fun (if you ask me ). Good work