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from a sanitary standpoint; but it can be understood that granaries, 

 bakeries, butcher shops, packing houses, dweUings, and other places, 

 if rat proofed for sanitary reasons, are just as much protected from 

 depredation of the rat as though the work had been performed for 

 commercial reasons alone. 



Rat proofing has a twofold objective. It serves as a protection 

 to the inmates of a building, and excludes rodents from sources of 

 food supplies and harboring places. While rat proofing should be 

 enforced as a general measure in all plague-infected localities, it is 

 imperatively demanded in premises whereon have occurred cdses of 

 human or rodent plague. 



Plague-infected localities or places that contain food must be 

 rendered imperviotis to rats in order to insure the success of other 

 preventive measures. Rats can be trapped or poisoned only when 

 other food supply is excluded. A rat will enter a trap for food or 

 will eat poisoned preparations not because of their greater attractive- 

 ness, but because of their greater availability. It therefore follows 

 that rat proofing of food supplies is a prerequisite to success in rat 

 eradication. The food depots requiring attention in the order of 

 importance are stables, meat markets, bakeries, restaurants, gro- 

 ceries, warehouses, and private dwellings. 



It is logical to suppose that the most common mode of infection 

 is by reason of plague rats dying in the walls, roofs, or floorings of 

 human habitations. As soon as the rat's body is cold the fleas 

 abandon it for another rat, some domestic animal, or human being. 

 The risk to human inmates in such infected houses, therefore, is 

 evident. 



That rat proofing is a valuable measure is shown by the reports 

 of the British Plague Commission where are mentioned the results 

 following the use of rat-proof "go-downs" and those not so con- 

 structed. Additional evidence is presented by the fact that 'appalling 

 epidemics of plague have ravaged India and the China coast, whereas 

 in the Philippine Islands but few people die of the disease. It would 

 appear that the comparatively few cases in the Philippine Islands 

 were due to the fact that most Philippine dwellings are rat proof 

 by reason of being elevated from the ground and the fact that the 

 walls are thin and offer no refuge whatever to rats. 



RAT PROOFING IS EXPENSIVE. 



The almost insuperable obstacle that will usually confront the 

 sanitary authorities in such work will be either the financial inability 

 of the unfortunate community or the sordid imwillingness to make 

 any expenditure that does not promise personal gain. 



When the influence of the mosquito in the transmission of yellow 

 fever was proven, recourse was had to mosquito proofing of both 



