Supplementary Video 1. Agkistrodon contortrix in Kentucky engaged in food-induced combat

Supplemental Video 3. Northern cottonmouths in North Carolina engaged in food-induced male-male combat

Osaka Museum of Natural History

Movie Archives of Animal Behavior

Four Agkistrodon conanti interact including engaging in food-induced male-male combat

Osaka Museum of Natural History

Movie Archives of Animal Behavior

Supplementary material 2 (Video). Changes in sailfish breathing from gill pump ventilation to ram ventilation

Osaka Museum of Natural History

Movie Archives of Animal Behavior

Supplementary material 1 (Video). “Pose” cleaning-request behavior of sailfish and response of marlin suckers

Osaka Museum of Natural History

Movie Archives of Animal Behavior

Warriors in Combat

Honolulu Museum of Art

Honolulu Museum of Art Collection

Warriors in Combat

Art Institute of Chicago

Art Institute of Chicago API

Supplementary material 3 (Video). “Cleaning-like” behavior of marlin suckers toward a sailfish

Osaka Museum of Natural History

Movie Archives of Animal Behavior

Supplementary material 1 (Video). The aggressive behavior of marked worker toward an attached worker

Osaka Museum of Natural History

Movie Archives of Animal Behavior

Comic Figures Engaged In Various Tasks

Dunedin Public Art Gallery

DigitalNZ New Zealand API

Kumagai and Atsumori in Combat

Minneapolis Institute of Arts

Minneapolis Institute of Art API

Video 1 Bobcat Body Rubbing

Osaka Museum of Natural History

Movie Archives of Animal Behavior

Bone marrow changes in adjuvant-induced and collagen-induced arthritis : IL-1 and IL-6 activity and abnormal myelopoiesis

NDL Digital Collections

NDL Digital Collections

Glibenclamide prevents coronary vasodilation induced by β[1]-adrenoceptor stimulation in dogs

NDL Digital Collections

NDL Digital Collections

[Village scene in Japan showing people engaged in various activities]

Library of Congress

Digital Collections, Library of Congress

Food safari. Series 2, episode 1, Japanese food safari

Stanford University Libraries

Stanford Libraries SearchWorks

New Food Products in Japan

Stanford University Libraries

Stanford Libraries SearchWorks

Japanese coolies engaged in the work of blasting rock

Auckland Libraries

DigitalNZ New Zealand API

Caspase-independent apoptosis induced by differentiation-inducing factor of D.discoideum in INS-1 cells

NDL Digital Collections

NDL Digital Collections

No. 1 (ichi), from the series "Women Engaged in the Sericulture Industry (Joshoku kaiko tewaza-gusa)"

Art Institute of Chicago

Art Institute of Chicago API

Supplementary material 2 (Video). The escape behavior of marked worker from an attached worker

Osaka Museum of Natural History

Movie Archives of Animal Behavior

[Battle scene - soldiers engaged in close fighting on a battlefield]

Library of Congress

Digital Collections, Library of Congress

Extensive cell death in thymocytes in colon 26-induced cachectic mice

NDL Digital Collections

NDL Digital Collections

Glomerular alterations in uranyl acetate-induced acute renal failure in rabbits

NDL Digital Collections

NDL Digital Collections

A second example of Agkistrodon piscivorus in North Carolina engaging in combat

Osaka Museum of Natural History

Movie Archives of Animal Behavior