The Common Field-Vole (Microtus or Arvicola agrestis) dwells in fields, and is at all times to be found in pastures, attracting little notice until, favoured by season and abundance of food, it multiplies into a plague. The grazier suffers most from this animal, the devastations to hill farmers on what is termed "bog" (strong marshy land, either grazed or mown for hay) being ruinous in some years; and from these breeding grounds the voles pass to young plantations, even nurseries and gardens, committing great havoc. The means of repression are almost as bad as the destruction caused by the voles when it takes the form of burning the grass and heather, for unless started from all points so as to enclose the vermin in a ring of fire, they are merely driven to fresh ground, while to burn all the roughness on a hill-farm is impracticable, as some part must be kept to support the stock. Nevertheless, it is really the soft bottom that encourages the voles, hence a periodical burning would be an advantage, thus keeping the bottom clear of useless vegetation as well as the vermin. But this cannot be carried out in woodland glades, hence recourse is had to trapping.

The most approved trap for voles is the Solid Ground Pitfall Trap (Fig. 94). It is dug in solid ground in places frequented by the voles, about 15 in. deep, 4 to 6 in. wide at the mouth, and sloping under the soil to a considerably wider bottom. Into this the voles fall, and are unable to escape; besides being exceedingly pugnacious, they kill one another in their efforts to escape. Possibly the Rattin that is employed in connection with rats and mice might afford the much needed relief in such attacks as those associated with Scotland in 1891 and 1892, for only on limited areas is pitfall destruction of the pests feasible.