Time to see at long last if the memory challenge theory was correct! Leg 10 had a couple, the cockroaches, and even if they didn't choose the alpaca task, it was in the name of the Detour in the clue.
Maybe it's the map puzzle, and once they finish building it, it also has China, Thailand and Panama on it, and they have to put representations of the animals in the right places on top of it. And maybe map out this crazy route as well.