Mice And Rats Advice
The house mouse, Mus musculus is a widespread, common and all too well known inhabitant of the UK, which probably arrived here in the baggage of our Neolithic ancestors some 4000 or 5000 years ago. It can be distinguished from the wood mouse by its greyer-brown fur. The wood mouse has much whiter feet and under parts and has no noticeable odour. Everybody knows that the house mouse inhabits houses and other buildings, but it is less well-known that they are also common in the countryside, breeding in the banks and hedgerows and taking to the warm abundance of corn silos in the winter. In corn silos, of course, they eat grain, and in buildings, whatever human stores or scraps they can find. Nothing, however, is known of their diet out in the fields, though presumably it consists largely of the seeds of wild plants, especially grasses, probably within admixture of insect food and whatever comes the way of this supreme opportunist among such small mammals.
One reason for the house mouse’s success is its capacity to breed all the year round in suitable sheltered habitats, such as attics or corn silos. There a female mouse may have as many as 10 litters a year, because the food supply problem is solved for her. In the average house food is a little harder to come by, so that the number of litters per year is more like five or six.
The brown or common rat, Rattus norvegicus, is undoubtedly our most disliked wild mammal, as it certainly is our most destructive one. It is also known as the Norway rat, from the belief that it was in timber boats from Norway that it originally invaded Britain in the first half of the 18th century. The common rat is now the most prevalent in industrial and commercial buildings in towns, cities, in sewers and in and around farms, from which it spreads out into the surrounding countryside in spring and summer. It's rather blunt muzzle, paler brown fur and shorter and stouter tail distinguish it from the now uncommon ship (Black) rat. It is in fact an altogether coarser looking animal and one of the few capable of inspiring a feeling of revulsion, even in a naturalist.
Large sums of money have been spent on official campaigns to reduce the number of common rats, which are especially destructive to grain and other stored products, but unfortunately, no rat poison has yet been discovered, which is both humane and effective.
The widespread destruction of their potential predators, such as stoats, and the larger birds of prey, in the supposed interests of game preservation, is probably one of the most important factors in the seemingly ineradicable occupation of the countryside by rats. In favourable habitats like grain silos, common rats, like the house mice, breed almost throughout the year.
The ship or black rat, Rattus rattus, used to be known, in the 18th century, when the common rat was beginning its invasion, as the old English rat, quite erroneously, for it was just as much an invader, having arrived in Britain in the middle ages, traditionally in the baggage of the returning Crusaders. It soon became almost as widespread as the common rat is today, but with the arrival of this larger, tougher, more ruthless competitor, it has been driven back into the ports, the centre of London and a handful of cities. In appearance, it is slenderer than the common rat, with fur, varying from brown to black, a sharper muzzle and a longer tail. It is even more agile than the common rat and more of a climber, being a tree dwelling species in some parts of the world. It can be equally destructive to stored grain and other foodstuffs, as well as destroying and fouling materials and is renowned for carrying disease.