Come on, people. Rat Colony deck is possibly the easiest thing to win against. It has simplistic and obvious game plan, people usually don't run proper answers or card draw and the card itself doesn't increase its toughness, having to trade with basically everything, including (but not limited to) saproling tokens, soldier tokens, vampire tokens and even Reassembling Skeleton. And you can wipe them with basically anything, including Golden Demise, Radiating Lightning, Shake the Foundations and Plague Mare. Heck, Dual Shot takes out two at once. If you face the deck regularly, just adapt a bit.
So basically if your deck doesn't generate a ton of tokens and it's not red or black then you're screwed? That's what it sounds like to me.
Rat Colony is a stupid card. It encourages players to make magic boring which isn't fun. Playing with or against that deck just kills all the fun. All I fought against were rat colony decks in the singleton event and it was dumb. I run into them in standard though as well rather frequently and they are still a major problem for me. I'm open to suggestions on how to counter it. It's easy with red or black or a deck that generates a million tokens. When I'm playing my mono blue deck though it's just dumb. Once they're on the board there doesn't seem to be anything I can do except maybe return some to their owner's hand. Is there a blue card that I'm unaware of that will deal 1 damage to them all, make them -1 or something that can deal with more than 1 rat at a time? Right now all I can find are counter creature spell and disperse spells.... which are not very effective at all against this since they have unlimited copies of the card and returning rats to their hand just delays the inevitable.
So basically if your deck doesn't generate a ton of tokens and it's not red or black then you're screwed? That's what it sounds like to me.