Stefan Christmann / Emperor penguin (Aptenodytes forsteri) two adults with chicks, age 9-12 weeks, Atka Bay, Queen Maud Land, Antarctica. October.

Mark Taylor / Tabby kittens, Stanley and Fosset, 12 weeks old, walking together.

Mark Taylor / Fluffy black kitten, 12 weeks old, stretching.

Mark Taylor / Tabby kittens, Stanley and Fosset, 12 weeks, walking together in unison.

Mark Taylor / Tabby kittens, Stanley and Fosset, 12 weeks, lounging together.

Petra Wegner / Mixed Breed puppy, 12 weeks / Pug crossbred, sitting on small sofa with reindeer toy.

Petra Wegner / Chihuahua, longhaired puppy, 12 weeks.

Colin Varndell / Red fox (Vulpes vulpes) two cubs of 12 weeks, Netherbury, Dorset, UK, July

Mark Taylor / Chocolate roan Cocker Spaniel puppy, Topaz, 12 weeks, running with ears flapping

Petra Wegner / Young Satin Lop-eared Dwarf Rabbit, white with rhon, 12 weeks

Petra Wegner / Lion-maned Dwarf Domestic Rabbit, young, 12 weeks

Jane Burton / Odd-eyed Border Collie pup, 12 weeks old, lying with black and white kitten, 6 weeks old