The animals that walk the Earth today are survivors; their ancestors adapted or moved to stay alive. So maybe rats will inherit the Earth, because they sure know how to live in a variety of environments.
And you notice: they're usually not far from people and all the things they use/eat/drop. Emma Marris is a freelance journalist based in Klamath Falls; she got knee-deep in rats (so to speak) for a recent piece in National Geographic. She visits to talk about some of the amazing feats rats are capable of.