THE MOUSE TRIBE. 135 
clothed with birch and juniper. Here they select dry spots in the swampy ground, 
making their shallow burrows either beneath stones or in the peaty soil. Generally 
they do not form well-marked tracks from one hole to another, except when the 
ground is covered with snow. They are on the move by day as well as by night. 
Except when migrating, lemmings show a great aversion to water, always selecting 
the driest portions of the swamps, and if forced to enter a river, manifesting their 
dislike by squeaks and grunts. Generally they sit quietly during the day, in or 
near the entrances of the burrows, but should a human being appear on the scene, 
they at once become violently excited, raising themselves up on their hind-quarters, 

NORWEGIAN LEMMINGS MIGRATING (4 nat. size). 
and squeaking, as if to warn him off from their territories, while their gestures are 
such as to give the impression that they are about to attack the intruder. Indeed, 
they will sometimes bite vigorously at the trousers of any person who approaches 
too close to their holes. The squeaks and grunts uttered on such occasions by the 
lemmings are said to closely resemble those of guinea-pigs. In the winter, they 
form large nests in their tunnels through the snow, which are exposed to view 
when it melts; several tunnels radiating from each nest, which are formed partly 
in the peat and partly in the snow. The chief food of the lemming in its native 
haunts consists of grass, reindeer-moss, the catkins of the birch, and probably 
various descriptions of roots. It appears that the young are born in the nests, 
which are usually made of dry grass with a lining of hair, and that there are 
