{"fact":"New Caledonian crows have demonstrated the ability to solve a string-pulling puzzle, repeatedly pulling and stepping on a string to access a reward.","context":"For this task, crows were presented with a reward that was tied to a dangling string. The correct solution required the crows to pull the string with its beak, step on the coiled string with its foot, and repeat until the reward was attained.","source":"Irina Meketa, A critique of the principle of cognitive simplicity in comparative cognition, 10.1007/s10539-014-9429-z","index":409}