D. Parer & E. Parer-Cook / Platypus (Ornithorhynchus anatinus) female swimming in water with courtship bite mark on tail, eastern Australia

Jeff Foott / American Beaver (Castor Canadensis) felled tree, Zion National Park, Utah

Jeff Foott / American Beaver (Castor Canadensis) felled tree, Zion National Park, Utah

Jeff Foott / American Beaver (Castor Canadensis) felled tree, Zion National Park, Utah

Jeff Foott / American Beaver (Castor canadensis) bite marks on tree, Zion National Park, Utah

Will Watson / Water Vole (Arvicola terrestris) feeding area with shredded Bulrush (Typha latifolia), Kent, England, June.

D. Parer & E. Parer-Cook / Platypus (Ornithorhynchus anatinus) female with courtship bite mark on tail, native to Australia

Jose B. Ruiz / Child with bite mark from Centipede {Scolopendra fasciculata} Spain

Mark Moffett / Leafcutter Ant (Atta laevigata) soldier bites photographer, carving through his skin in just the same way medium-sized workers bite leaves, near Sao Paulo, Brazil

Flip Nicklin / Humpback Whale (Megaptera novaeangliae) fluke with barnacles and around round from Cookie-cutter Shark bite, Maui, Hawaii

Ingo Arndt / European Beaver (Castor fiber) fresh bite marks and felled trees, Spessart, Germany

Ingo Arndt / European Beaver (Castor fiber) fresh bite marks on gnawed tree, Spessart, Germany