{"fact":"It takes patience to teach a crow a new trick.  Two crows in a study didn't use tools until researchers slowly showed them how by moving the tool closer and closer to the target over time!","context":"However, these birds were successfully trained through gradual changes in the position of a tool (metal rod) in the test chamber (positional fading).","source":"Robert W. Powell; William Kelly, Tool use in captive crows, 10.3758/bf03337704","index":4}