
Rodents can be trained to use tools and understand their functions, a Japanese study said Wednesday, challenging a view that only primates and some birds are smart enough. Six adult "degus" rodents, a kind of small rat, were trained at a laboratory at the Japanese government-funded RIKEN research institute and all of them were able to use a tiny T-shaped rake to retrieve food, it said. In the final stage of the 60-day experiment, they were pulling the tool towards themselves to hold onto it and then moving it to obtain food, the study showed. "A conventional view holds that the use of tools is a high-level ability, but animals in the class of rodents can do it if they are trained accordingly," said Kazuo Okanoya, who heads the study team...The findings suggested that a wide range of animals could use tools, although it may be doubtful for fish, he said...more...