Ingo Arndt / American Bison (Bison bison) head portrait of male licking nostril with tongue, South Dakota, USA

Jen Guyton / Southern giraffe (Giraffa camelopardalis) licks its own nostril in Hluhluwe-Imfolozi park, South Africa.

Chris Mattison / English Longhorn cattle, licking nostril with tongue, Derbyshire, UK

Tony Wu / Humpback whale (Megaptera novaeangliae) close up of female with open nostrils surfacing to breathe, note the whale lice (Cyamus boopis) Vava'u, Tonga, South Pacific

Richard Du Toit / White Rhinoceros (Ceratotherium simum) nostrils and mouth, Rietvlei Nature Reserve, South Africa

Daniel Heuclin / Western lowland gorilla (Gorilla gorilla gorilla) male head portrait, captive in zoo, native to west Africa.

Roland Seitre / Bald head uakari monkey (Cacajao calvus rubicundus) captive, occurs in Amazonian Peru, and Brazil.

Franco Banfi / Walrus (Odobenus rosmarus) face at sea surfaceSpitsbergen, Svalbard Archipelago, Norway, Arctic Ocean. July.

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) in water sneezing and expelling sodium from nostril and cranial salt gland, Punta Espinosa, Fernandina Island, Galapagos Islands, Ecuador

Flip Nicklin / Long-beaked Common Dolphin (Delphinus capensis) surfacing, Baja California, Mexico

D. Parer & E. Parer-Cook / Platypus (Ornithorhynchus anatinus) swimming in water, close up of pliable bill with nostrils, eastern Australia

Hiroya Minakuchi / Gray Whale (Eschrichtius robustus) calf breathing through open blowhole at surface, San Ignacio Lagoon, Baja California, Mexico