Red squirrels used to be a common right in British forests and countryside. However, fewer than 140,000 individuals are thought to be left and most of them are found in Scotland. In contrast, grey squirrels are now so common they are seen as a pest and can be legally trapped and destroyed. The population decrease in red squirrels is claimed to be due to the introduction of the grey squirrels from North America, but disease and the loss of its native woodland habitat have also played a major role in the decline of the red squirrels in Britain.