FIGURE 8.5 Tool-using animals (a) Crows studied by (yes) Christopher Bird and Nathan Emery (2009) quickly learned to raise the water level in a tube and nab a floating worm by dropping stones into the water. (b) One male chimpanzee in Sweden’s Furuvik Zoo was observed every morning collecting stones into a neat little pile, which later in the day he used as ammunition to pelt visitors (Osvath & Karvonen, 2012).

Chris Bird & Nathan Emery

Neurology/PA/AP Photo