{"fact":"Crows seem to use vision to plan their tool-use movements, as blocking their view makes their tool movements less accurate.","context":"Visual blocking affected tool movement trajectories for all three crows.","source":"Masaki Kanai; Hiroshi Matsui; Shigeru Watanabe; Ei-Ichi Izawa, Involvement of vision in tool use in crow, 10.1097/wnr.0000000000000229","index":61}