A bot would be able to solve that challenge really easily though. And if you put a CAPTCHA in there? It would be really trivial to have someone watching and just pop up a status window to request input of the code from the operator. Remember, most bots do not use the same game client that we do, they have their own client which lets them do things like drop underground or teleport around the map to each node for gathering. Also it doesn't hurt to think like a cheater once in a while