But the structure of the water-rat gives no indication of its habits, so that no one who was unacquainted with the animal would even suspect its swimming and diving powers. Watch it as long as you like, and I do not believe that you will see it eating anything of an animal nature.
I mention this fact because it is often held up to blame as a mischievous animal, especially deserving the wrath of anglers by devouring the eggs and young of fish.
As is often the case in the life-history of animals as well as of men, the blame is laid on the wrong shoulders. If the destruction of fish be a crime, there are many criminals, the worst and most persistent of which are the fish themselves, which not only eat the eggs and young of other fish, but, Saturn-like, have not the least scruple in devouring their own offspring.
Scarcely less destructive in its own insidious way is the common house-rat, which eats everything which according to our ideas is edible, and a good many which we might think incapable of affording sustenance even to a rat. In the summer time it often abandons for a time the house, the farm, the barn, and seeks for a change of diet by the brook. These water-haunting creatures are naturally mistaken for the vegetable-feeding water-vole, and so the latter has to bear the blame of their misdoings.
There are lesser inhabitants of the brook which are injurious both to the eggs and young of fish. Among them are several of the larger water-beetles, some of which are so large and powerful that, when placed in an aquarium with golden carp, they have made havoc among the fish, always attacking them from below. Although they cannot kill and devour the fish at once, they inflict such serious injuries that the creature is sure to die shortly.
I do not mean to assert that the water-vole is never injurious to man. Civilisation disturbs for a time the balance of Nature, and when man ploughs or digs the ground which had previously been untouched by plough or spade, and sows the seeds of herbs and cereals in land which has previously produced nothing but wild plants, he must expect that the animals to whom the soil had been hitherto left will fail to understand that they can no more consider themselves as the owners, and will in consequence do some damage to the crops.
Moreover, even putting their food aside, their habits often render them obnoxious to civilised man. The mole, for example, useful as it really is in a field, does very great harm in a garden or lawn, although it eats none of the produce.
The water-vole, however, is doubly injurious when the field or garden happens to be near the water-side. It is a mighty burrower, driving its tunnels to great distances. Sometimes it manages to burrow into a kitchen-garden, and feeds quite impartially on the different crops. It has even been seen to venture to a considerable distance from water, crossing a large field, making its way into a garden, and carrying off several pods of the French bean.
In the winter time, when other food fails, the water-vole, like the hare and rabbit, will eat turnips, mangold-wurzel, the bark of young trees, and similar food. Its natural food, however, is to be found among the various aquatic plants, as I have often seen, and the harm which it does to the crops is so infinitesimally small when compared with the area of cultivated ground, that it is not worthy of notice.
Still, although the harm which it does to civilised man in the aggregate is but small, even its most friendly advocate cannot deny that there are cases where it has been extremely troublesome to the individual cultivator, especially if he be an amateur.