The report states, that the carcases of horses killed one day, and amounting to thirty-five, would be found the next morning with the bones picked clean. A person of the name of Dusaussois, belonging to the establishment, made this experiment. A part of his yard was enclosed by solid walls, at the foot of which, several holes were made for the entrance and exit of the rats. Into this enclosure he put the bodies of three horses, and in the middle of the night he stopped up all the holes as quietly as he could; he then summoned several of his workmen, and each, armed with a torch and a stick, entered the yard, and carefully closed the door. They then commenced a general massacre; in doing which, it was not necessary to take aim, for wherever the blow fell, it was sure to knock over a rat, none being allowed to escape by climbing over the walls. This experiment was repeated at intervals of a few days, and at the end of a month, 16,050 rats had been destroyed. In one night they killed 2,650; and yet this cannot give an entirely adequate idea of their number, for the yard in question did not cover more than a twentieth part of the space allotted to killing horses. The rats in this place have made burrows for themselves, like catacombs; and so great is their number, that they have not found room close by the slaughter-houses. They have gone farther; and the paths to and from their dwellings may be traced across the neighbouring fields.
The Zoological Gardens in the Regent's Park, are greatly infested by rats; but they are too cunning to stay there during the day time, when they might be more easily caught; so they in the morning cross the canal to the opposite shore, and return in the evening to commit their depredations.
The Water-rats, or Voles, eat fishes, frogs, and toads, besides other food, and do infinite mischief to banks and dams, which they undermine. Their smell is so acute, that they will not approach a trap over which a hand has been passed; and they are particularly abundant in all places where herrings are cured, leaving them when the season is over. The thing of all others which attracts rats of all kinds, is a piece of roast beef; of which they are so fond, that they have been known to kill a companion who has eaten some, that they might devour the contents of his stomach.