“…A raking tool was used for the behavioral task for rats in the present study because the previous studies have reported that degus and rats could use rake-shaped tools ( Kumazawa-Manita et al, 2013 ; Nagano and Aoyama, 2017a , b ; Nagano, 2019a , b , 2021 ), and the animals in the present study were expected to learn to use the raking tool in a shorter period because it is easier for them to handle the tool with their forelimbs. Tool-use behavior in rats in the wild has never been reported ( Bentley-Condit and Smith, 2010 ), and spontaneous tool-use behavior has never been observed in the experimental settings ( Nagano and Aoyama, 2017a , b ; Nagano, 2019a , b , 2021 ). However, rats are skillful in using their forelimbs dexterously to pull strings to obtain a food ( Blackwell et al, 2018 ).…”