{"fact":"New Caledonian crows don't just randomly pull strings!  They're much more likely to pull a string if they know a tasty treat is attached.","context":"Eleven of the 12 crows chose the string with the meat rather than the rock on their first trial. Therefore, string-pulling by New Caledonian crows is goal-directed because these crows do not pull up string irrespective of the object at its end.","source":"Alex H. Taylor; Douglas Elliffe; Gavin R. Hunt; Russell D. Gray, Complex cognition and behavioural innovation in New Caledonian crows, 10.1098/rspb.2010.0285","index":267}