Jed Weingarten / Wild Wonders of China / Tibetan macaque baby (Macaca thibetana) chewing on his thumb, Tangjiahe Nature Reserve, Sichuan Province, China, April.

Remi Masson / European bullhead (Cottus gobio) camouflaged among rocks and aquatic plants, Ain, Alps, France

Remi Masson / Two European bullhead fish (Cottus gobio) hiding among rocks in small river, Ain, Alps, France

Remi Masson / European bullhead (Cottus gobio) on riverbed of small river, Ain, Alps, France, May.

Ashley Cooper / Frozen hand print on an iced over car window, Ambleside, Cumbria UK. December 2008

Tony Wu / Fisherman holding deep-sea Rockcod (Sebastes matsubarai) on fishing boat. Suruga Bay, Shizuoka Prefecture, Honshu, Japan. April 2018.

Paul Williams / Oyayubi Iwu Peak 'the thumb' (3975.8 m) and the pinnacles. Mount Kinabalu, Borneo. May 2013.

Paul Williams / Oyayubi Iwu Peak 'the thumb' (3975.8 m) and the pinnacles. Mount Kinabalu, Borneo. May 2013.

Ingo Arndt / Orang utan holding twig and feeding {Pongo pygmaeus abelii} Gunung Leuser NP, Sumatra

Nick Upton / Redshank / Spotted ladysthumb (Persicaria maculosa) flowering on riverbank, Wiltshire, UK, July.

Nick Upton / Redshank / Spotted ladysthumb (Persicaria maculosa) flowering on riverbank, Wiltshire, UK, July.

Chris Mattison / Tarthuth (Cynomorium coccineum) a parasitic desert plant pollinated by flies. United Arab Emirates, February.