100 million years in the future, the time of the mammals is long past. The changing temperature and atmosphere of the planet are encouraging the growth of arthropods (insects, arachnids, crustaceans, etc.) and the only mammals left are strange, highly specialized creatures.

Within the depths of Silver Spider colonies, collected grass seeds are stacked against the rocky walls, packing the cracks between stones, and piled in loose pyramids. The spiders come and go, adding to the heaps all the time. Sometimes inside some of the piles, something moves. The little furry face of a Poggle will peep out, a small, shy rodent with rounded ears and big eyes peering around in the darkness. These furry creatures are one of the last surviving mammals on Earth, living within the silver spider colonies, sleeping in crevices that the spiders do not enter, and feeding on the grain stored with such effort by the silver spiders.