Throughout the Cenozoic era the rodents were one of the most successful animal groups in the coniferous forests. Their powerful teeth enabled them to cope with the tough vegetable matter found there and their warm, furry coats helped them to retain body heat during hibernation. No other small rodent found in the coniferous forest is quite so destructive. Most live on shoots, bark and the seeds found in cones. Many are ground dwellers and feed from the cones where they fall. Others are lightly built and agile enough to scramble along the branches to where the cones are actually growing.