THE HOUSE RAT 5 



scarcity. They subsist largely upon food produced by man and are 

 consequently most abundant where foods for human consumption are 

 raised and stored in greatest quantity. Their number therefore can 

 be expected to be more or less proportionate to the number of people, 

 except in the larger cities. 



In large cities rats have declined at a very gratifying rate — prob- 

 ably 50 percent or more — in the past 20 years. This has been due 

 to the generally improved sanitary conditions, to modern rat proof 

 construction, to the passing of the horse, to the improved packaging 

 of foods, to the elimination of waste food products, and to the greatly 

 increased resistance of city residents to rats. Twenty years ago 

 markets, livery stables, commission houses, grocery stores, warehouses, 

 and most other business establishments supported large numbers of 

 rats. Today customers avoid rat-infested stores and patronize estab- 

 lishments where they know the merchandise will be kept clean and 

 uncontaminated. Twenty years ago there was easily one rat for 

 every person in almost every city. Today it is estimated that the 

 ratio has declined to not more than one rat to each two persons. 



In the smaller agricultural towns the picture is different. Although 

 much improvement has been made in rat control, progress has been 

 much less rapid. Proportionately less concrete is used than in cities, 

 and facilities for disposing of garbage and trash are often lacking. 

 Also, many town dwellers keep chickens and other domestic stock, 

 and thus the insistence on strict municipal cleanliness is sometimes 

 less pronounced. This is not true of all small towns, of course, but 

 it is the average condition. In small towns the rat population 

 probably equals the human population. 



There are considerably more rats on farms than in cities and 

 towns, because of the normally more abundant food supply and the 

 greater opportunities for rat harborage. Although many farms are 

 kept free from rats, experience gained in organizing rural antirat 

 campaigns indicates that the percentage of rat-free farms is small. 

 There are many records, in fact, of several hundreds, and even 

 thousands, of rats being taken from individual farms. The par- 

 ticipants in a rat-killing contest in one county in Texas some years 

 ago turned in, by actual count, 153,720 rat tails in 6 week's time. 

 The human population of the county was only 35,000. In January 

 1934, during a campaign for rat control in connection with typhus- 

 fever control in Georgia, Alabama, and Texas, 623,071 rats were 

 trapped on 230,737 premises after the bulk of the rats on the premises 

 had been destroyed by poisoned bait. It was estimated that in all 

 more than 7,500,000 rats were destroyed on 747.608 premises treated, 

 or approximately 2 rats per person living on the premises. Not all 

 the rats were killed, of course, and the premises treated included town 

 as well as rural properties. 



The rat population of farms is greater in the northern than in the 

 southern part of the United States. This is explained by the fact 

 that in the South a larger proportion of nonedible crops, such as 

 tobacco and cotton, are produced, that southern farm families more 

 frequently live in towns, and that their houses and other structures 

 are often built on posts well above the ground, thus eliminating the 

 acceptable underfloor rat harborage. The number of rats on farms 

 has diminished to some extent with the increased intolerance of their 



