THE BROWN RAT 
When asleep, the Rat curls its body into a ball with the forehead placed 
on the ground and the nose tucked under the chest and between the forepaws. 
A dark variety of the Common Rat, entirely black in colour except for 
a patch of white on the breast, was first observed in Ireland and described by 
Thompson in 1837, who considered it nearly allied to the Black Rat [Mus 
rattus). It has since been shown to be merely a melanistic form of Mus 
decumanus, which occurs in the Outer Hebrides and also in various English 
counties, where it appears to be spreading in increased numbers. 
