Rats are probably a lot more intelligent than we think.
A number of rats were trained to tell the difference between a short and a long burst of noise. They then had to tell the researchers whether it was a long or short noise by pressing a lever.
If they got the answer right, they would get a larger reward of treats. If their answer was wrong, they did not get any reward. If they chose not to answer, they got a small number of treats.
They were usually able to choose correctly. When it was too difficult to classify the noise as “short” or “long”, because it was in between the two, the rats chose not to answer, showing that they understood they might give the wrong answer.
Previously, scientists thought that only humans and other members of the primate family were capable of this type of understanding. This shows us again that many other animals have unsuspected depths and abilities.
