Doug Gimesy / Grey-headed flying foxes (Pteropus poliocephalus) carrying her pup attached to a teat. Yarra Bend Park . Kew, Victoria, Australia.

Ashley Cooper / Milking sheep on a farm in Lazonby, Cumbria, England, UK, August.

Nick Upton / Eurasian beaver (Castor fiber) female grooming on the margins of the River Otter, Devon, UK, July. Part of Devon Wildlife Trust's Devon Beaver Trial.

Roland Seitre / White Bengal tiger (Panthera tigris tigris) cub suckling, aged 5 days. Olmen zoo, Belgium. Captive, occurs in India, Bangladesh, Nepal and Bhutan. Endangered species.

Nick Upton / Adult female Edible / Fat Dormouse (Glis glis), the mother of a large litter of young and showing obvious teats, being held in a leather glove during a monitoring project in woodland where this Europe...

D. Parer & E. Parer-Cook / Tammar Wallaby (Macropus eugenii) newborn attached to teat in pouch, Australia

Edwin Giesbers / Wild boar (Sus scrofa) piglet suckling from mother's teat, the Netherlands, April

John Cancalosi / Common brushtail possum {Trichosurus vulpecula} young suckling on teat in mother's pouch, Australia, captive

Rob Tilley / Japanese Macaque / Snow monkey (Macaca fuscata) at teat of mother, Jigokudani, Nagano, Japan

Jane Burton / Domestic Cat {Felis catus} 1-day blue kitten with medicine dropper and teat to supplement feed.

Suzi Eszterhas / Eastern grey kangaroo (Macropus giganteus) joey, aged one year, suckling from teat within mothers pouch, Brisbane, Australia. Captive.

Milan Radisics / Red fox (Vulpes vulpes) vixen investigating bird table in garden at night, looking for food. Vertes Mountains, Hungary. The female's teats are visible in the image, showing that she was suckling...