These adorable little mammals, just 6.5-8 cm in length, are nocturnal and spend almost all their time during the summer, hidden up in the tree canopy, very rarely coming down to ground level. Although they can occasionally be found in abandoned birds nests they do weave their own, often in brambles or in other shrubs. They build these using materials such as strips of honeysuckle bark which they then surround with a layer of green leaves. When conditions are cold or wet, or if food is scarce,  dormice curl up tightly into a ball. In order to save energy they have the ability to survive for a short time in a hibernation-like state called torpor. The growing human population, habitat fragmentation and the loss of woodlands has led to the reduction of suitable habitats  resulting in the alarmimg drop in the native dormouse population.