132 RODENTS. 
night and day, although it is more active during the dark hours. In addition to 
these runs, the field-vole also constructs burrows of considerable size. The food of 
this species consists of seeds, roots, and herbage of all kinds. In gardens it 
displays an especial taste for the bulbs of crocuses and newly-sown peas and beans, 
among which it frequently does great damage. In winter, when other food is 
scarce, the field-vole will not unfrequently ascend trees to feed upon their bark. 
It is also by no means averse to a diet of insects and flesh. 
The field-vole is an unusually prolific animal, producing from three to four 
litters in a year, and each litter containing from four to six young. The nest in 
which these are born is composed of moss and leaves, and is usually placed beneath 
a tussock of grass in some slight hollow in the ground. 
The most remarkable peculiarity in connection with this field-vole is the 
swarms in which it occasionally makes its appearance in various parts of the 
country. According to Mr. J. E. Harting, one such “mice-plague” appeared in 
1580 in Essex, a second visited Hampshire and Gloucestershire during 1813-14, 
while a third was recorded in Wensleydale which lasted from 1874 to 1876. In 
the second of these visitations, upwards of thirty thousand voles were destroyed in 
the Forest of Dean, and eleven thousand five hundred in the New Forest. Quite 
recently (1892), another such plague has made its appearance in the south of Scot- 
land, especially in parts of Dumfriesshire and Roxburgh; the area over which the 
voles extended being estimated at from eighty thousand to ninety thousand acres. 
The mildness of the winter of 1890-91, coupled with the scarcity of owls, kestrels, 
and weasels (due to the over-zeal of gamekeepers), are supposed to have been the 
inducing cause of this last visitation. It is reported, however, that, as on similar 
occasions, numbers of owls arrived in the affected districts for the purpose of prey- 
ing on the voles, which by the end of 1893 had well-nigh disappeared. 
The habits of the continental field-vole are similar to those of the English 
species. It is stated, however, to be even a more prolific animal, the number of 
young varying from four to eight, while as many as six different litters may be 
produced in a single season. Moreover, it is probable that the young produced in 
the spring will themselves be parents in the following autumn. On the Continent 
the plagues of voles are even more serious than in England. Thus, according to 
Brehm, during a visitation of these animals which took place in Germany in the 
year 1822, upwards of 1,570,000 were taken in one district, 590,327 in another, and 
271,941 in a third. Again, in the summer of 1861, a total of 409,523 voles were 
taken in a single district of Rhine-Hessen. 
The third species of the genus in Britain is the bank-vole 
(M. glareolus), which may be distinguished externally from the field- 
vole by the colour of the back inclining more or less markedly to rufous, and also 
by its larger ears, and proportionately longer tail, which is equal to half the length 
of the head and body. The molar teeth differ from those of the field-vole not 
only by the circumstance that in the second one of the upper jaw there are but 
four prisms, but also in that in the adult state these teeth form imperfect roots. 
The whole proportions of the bank-vole are more elegant than those of the field- 
vole, while its fur is more smooth and glossy, its coloration more brilliant, and the 
eye larger. It is found locally over England and parts of Scotland, as far north as 
Bank-Vole. 
