{"fact":"Think opening a matchbox is easy?  Crows figured out how to open a matchbox to get at the tasty treats inside!","context":"The second problem consisted of placing a number of matchsticks inside a cardboard matchbox (11.2 x 6.5 x 3.6 cm high) with a small aperture through which the matchsticks were visible. Here the crows usually pecked at the aperture and pulled at it with one foot, until the box was open a sufficient distance so that matchsticks could be removed.","source":"Robert W. Powell; William Kelly, Tool use in captive crows, 10.3758/bf03337704","index":3}