as Enemies of Mankind. 



7 



nests of grass, rags, paper, or other soft materials, placed in their 

 holes or burrows. Into these retreats they habitually carry much 

 food, so that when circumstances do not permit of foraging 

 expeditions {e.g., during bad weather out of doors, or when danger 

 threatens within) they are able to remain concealed and secure 

 for a considerable time. They seek to establish their nests as 

 near to their food-supply as possible, but often undertake quite 

 considerable journeys to other feeding places. If the latter are 

 far from home, temporary hiding-places are usually established ; 

 and if the new food-supply be attractive, such temporary refuges 

 may be converted into permanent dwellings and the old nest 

 abandoned. On their journeys they follow definite paths or runs, 

 from which they rarely deviate voluntarily. In the open, these 

 runs are readily found, and may be distinguished from those of 

 rabbits by the continuously smoothened surface and the spindle- 

 shaped droppings. In buildings, the runs are no less definite, and 

 they maybe found by sprinkling the floor with powdered materials. 

 In rooms, they usually keep close to the walls, sometimes on the 

 floor and sometimes along skirtings or pipes. Eats are extremely 

 wary, and highly suspicious of traps ; but they may be frequently 

 caught by unbaited traps, if the latter be properly set in their 

 runs. While grain may be considered their staple food, they 

 greedily devour everything edible that comes in their way, be it 

 animal or vegetable. Like all other rodents, rats have to gnaw 

 hard substances regularly in order to keep their ever-growing 

 incisors at a proper length ; in default of wood for this purpose 

 rats will attack all sorts of materials — leather, bone, ivory, lead 

 pipes and sash-weights, brick, and even cement being among such 

 substitutes. 



B. rattus is essentially an arboreal or climbing animal, and it 

 rarely burrows ; hence, where infesting buildings or huts, it is 

 found usually in the walls, ceilings, or roof, not in cellars or 

 drains. Although cautious, it does not shun mankind, and it 

 enters into far closer relations with its unwilling host than does 

 the Brown Eat. For this reason it is often the species principally 

 concerned in the transmission of plague. It drinks little, and 

 seldom, if at all, enters water voluntarily. As already mentioned, 

 this is the common rat on ships. In most cases it reaches or 

 leaves the ships by climbing their cables while they are in dock ; 

 sometimes it is introduced with grain and other merchandise. Its 

 diet is of a most varied description, but, probably in consequence 



B 



