A group of critically endangered, extremely rare Visayan warty pigs at the Ménagerie Zoo in Paris were witnessed unexpectedly utilizing a piece of wood as a tool while building a nest for their offspring. Both males and females took part in using this specific tool.
Here, we report the first structured observations of umprompted instrumental object manipulation in a pig, the Visayan warty pig Sus cebifrons, which we argue qualifies as tool use. Three individuals were observed using bark or sticks to dig with. Two individuals, adult females, used the sticks or bark, using a rowing motion, during the final stage of nest building. The third individual, an adult male, attempted to use a stick to dig with.