Kerstin Hinze / Hazel dormouse (Muscardinus avellanarius), caught in a wooden box by scientists, Voeren, Wallonia, Belgium. September.

Kerstin Hinze / Hazel dormouse (Muscardinus avellanarius), climbing a walnut tree, Wallonia, Belgium. September.

Kerstin Hinze / Hazel dormouse (Muscardinus avellanarius), climbing a walnut tree, Wallonia, Belgium. September.

Kerstin Hinze / Hazel dormouse (Muscardinus avellanarius), climbing a walnut tree, Wallonia, Belgium. September.

Kerstin Hinze / Hazel dormouse (Muscardinus avellanarius), climbing a walnut tree, Wallonia, Belgium. September.

Kerstin Hinze / Two Hazel dormice ( Muscardinus avellanarius), in nest, Hesse, Germany, October.

Colin Varndell / Dormouse (Muscardinus avellarius) pregnant female, Dorset, UK July.

David Kjaer / Common dormouse (Muscardinus avellanarius) in nest box, Wiltshire, England, UK, May.

Kim Taylor / Hazel Dormouse (Muscardinus avellanarius) in Wychelm tree in early spring. Italy, April.

Kerstin Hinze / Hazel dormice (Muscardinus avellanarius), together in one nest, Harz, Saxony-Anhalt, Germany, June.

Kerstin Hinze / Hazel dormouse (Muscardinus avellanarius), adult male, climbing on flowering Honeysuckle, Germany, June.

Ann & Steve Toon / Hazel dormouse (Muscardinus avellanarius), in researcher's hand, Nottinghamshire, UK, June