I'm just wondering, do faucet owners "babysit" their faucets? Is it a constant watch and fight against bots/scammers? I probably know the answer seeing so much 'double your btc' and the likes.
From what I can see and hear from other faucet owners, yes. Since you have had a possible bot visit your faucet, they may come back with another address/ip. You will have to consistently look out for this to stop your faucet being botted.
Try to be sure that you distinguish legitimate members from bots however. Install Google Analytics and see what site refers users to your faucet. It may give an idea on whether it's a bot or just an advertising campaign/rotator.