Alex Hyde / Group of Tissue moths (Triphosa dubitata) hibernating in a limestone cave. Peak District National Park, Derbyshire, UK. November.

Thomas Marent / Geometer Moth (Cathydata batina), Tatama National Park, Colombia

Paul Bertner / Looper Moth (Geometridae) caterpillar, Bukit Barisan Selatan National Park, Sumatra, Indonesia

Lorraine Bennery / Geometrid moth caterpillar (Geometridae sp.) moving along a twig in classic pose, Corbieres, France, May.

David Kjaer / Duke of Burgundy butterfly (Hamearis lucina), Wiltshire, UK, June.

Jussi Murtosaari / Grey Birch butterfly (Aethalura punctulata) resting on tree trunk in woodland habitat, Pirkanmaa, Finland, May.

Piotr Naskrecki / Looper Moth (Geometridae) caterpillar with aposematic coloration, Atewa Range, Ghana

Chris Mattison / Scalloped hazel moth (Odontopera bidentata), Wye Valley, Monmouthshire, Wales, UK. May.

Chris Mattison / Oak beauty moth (Biston strataria) resting on lichen. Wye Valley, Monmouthshire, Wales. March, UK. Focus-stacked image.

Chris Mattison / Scalloped hazel moth (Odontopera bidentata) on white background. Wye Valley, Monmouthshire, Wales, UK. May.

Chris Mattison / Scalloped hazel moth (Odontopera bidentata) on leaf. Wye Valley, Monmouthshire, Wales, UK. May.

Chris Mattison / Pale brindled beauty (Phigalia pilosaria) on white background. Wye Valley, Monmouthshire, Wales, UK. February.

Yuri Shibnev / Siberian flying squirrel (Pteromys volans) on tree trunk, Ussuriland, South Primorskiy, Far East Russia

Benjam Pontinen / Siberian flying squirrel in nest {Pteromys volans} Finland.

Benjam Pontinen / Siberian flying squirrels in nest {Pteromys volans} , Finland.

Yuri Shibnev / Siberian flying squirrel food hoard (Pteromys volans) Russia Ussuriland, South Primorskiy

Benjam Pontinen / Siberian flying squirrel looking out of nest hole in tree {Pteromys volans} Finland, Europe

Benjam Pontinen / Siberian flying squirrel feeds in alder tree. Nurmo, Finland.

Tony Wu / Siberian flying squirrel (Pteromys volans orii) emerging from nest hole in tree at dusk. Hokkaido, Japan. March.

Tony Wu / Siberian flying squirrel (Pteromys volans orii) eating buds in tree. Hokkaido, Japan. March.

Tony Wu / Siberian flying squirrel (Pteromys volans orii) feeding on Sakhalin fir tree. Hokkaido, Japan. March.

Tony Wu / Siberian flying squirrel (Pteromys volans orii) sitting in tree at dusk. Hokkaido, Japan. March.

Tony Wu / Siberian flying squirrel (Pteromys volans orii) emerging from nest hole in tree trunk. Hokkaido, Japan. March.

Nick Upton / Felled conifer trees stacked beside forestry track through mixed forest. Near Muraka Forest Reserve, a rare surviving home for Siberian flying squirrel (Pteromys volans). Near Lisaku, Estonia. April 2...