Espen Bergersen / Common raven (Corvus corax) pair in courtship display, flying upsidedown and calling, Hornoya bird cliff, Norway. March.

Jorma Luhta / Two Red squirrels {Sciurus vulgaris} on tree trunk, one going up, one coming down, Finland

Anup Shah / Sumatran Orang utan baby hanging upsidedown in tree {Pongo pygmaeus abelii} Gunung Leuser NP, Sumatra, Indonesia

David Fleetham / Upsidedown jellyfish (Cassiopea medusae) resting in water, Komodo, Indonesia.

Claudio Contreras / Upsidedown Jelly (Cassiopea frondosa), Jardines de la Reina / Gardens of the Queen National Park, Caribbean Sea, Ciego de Avila, Cuba, January

Ingo Arndt / Goldenrod crab spider {Misumena vatia} Germany

Pete Oxford / Mangrove upsidedown jelly (Cassiopea xamachana) Lighthouse Reef Atoll, Belize.

Pedro Narra / Young Bornean Orangutan (Pongo pygmaeus) hanging upsidedown, Camp Leakey, Tanjung Puting National Park, Central Kalimantan, Borneo, Indonesia.

Markus Varesvuo / Bearded Tit (Panurus biarmicus) female amongst reeds collecting seeds, Finland

Alex Mustard / Harlequin shrimp (Hymenocera elegans) on blue sea star. This species of shrimps feeds on starfish, turning them upsidedown and keeping them as living larder. Bitung, North Sulawesi, Indonesia. Lembeh...

Pat Tuson / Transition Towns Stall surrounded by people with upsidedown bicycles in front, London Green Fair (previously Camden Green Fair) England UK, June 2011

Georgette Douwma / Upside down jellyfish (Cassiopeia andromeda) on sea bed, Rinca, Komodo National Park, Indonesia, October