66o 



NATURE 



[May 20, 1922 



There are no financial provisions for the Rats Act's 

 working to be found in the Act ; it is punishable with 

 a fine to harbour rats, yet reinfestation of a cleared 

 habitation is not punishable, nor is trafficking in 

 rats a crime. These weaknesses are being remedied 

 in a Bill being drafted by the Incorporated Vermin 

 Repression Society to amend the existing Act. The 

 I.V.R.S. memorialised the League of Nations, and 

 incidentally the memorial was signed by leaders of 

 all shades of thought, with the view of securing an 

 International Conference to deal with rats and 

 shipping (the existing regulations being chaotic and 

 tending to discriminate against this country) and to 

 give a ruling on the vexed question of the employ- 

 ment of virus. 



The virus question is one that should be settled 

 without delay. Those — Uke the I.V.R.S.— who oppose 

 its use, argue that it is unsound in principle to permit 

 the unrestricted use of living virus, or germs, of 

 mouse typhoid or any other disease which might 

 possibly become communicable to man, and that, 

 moreover, it is a waste of hioney and opportunity 

 to create a race of rats immune to the effects of 

 virus in the process of killing what is, after all, an 

 infinitesimal proportion of the rat population. 

 Attempts to get manufacturers interested in the 

 production of virus to agree to a round table con- 

 ference with unbiassed bacteriologists, pathologists. 

 Government representatives and business men, have 

 unfortunately, so far, been unsuccessful. 



The question is often asked — " What is the best 

 method of destroying rats ? " There is only one 

 answer — " There is no best method of destroying 

 these pests." Rat destruction is a problem of 

 urgency, and also one of extreme difficulty, and a 

 moment's reflection shows that this difficulty cannot 

 be dismissed with a shrug of the shoulders, because 

 the rat is far too clever to be caught except in 

 negligible numbers by any crude method. It is an 

 omnivorous feeder, and since the rat's diet compre- 

 hends bacon, bananas, eggs, lamb, young chicks, 

 offal, bread, sponge-cakes, young rabbits, young 

 game, biscuits, human flesh, apples, sweetbreads, 

 corn, bulbs, and other eatables too numerous to 

 mention, it is hopeless to pin one's faith to poisoning, 

 since all poisoning, that is to say, effective poisoning, 

 is a matter of baits. Again, this method of destroy- 

 ing rats demands fool-proof preparations, which limits 

 the field in this respect ; obviously it is dangerous to 

 place poisons such as arsenic, strychnine, antimony, 

 phosphorus and the like in places accessible to children 

 or domestic animals ; therefore, for all practical 

 general purposes we are limited to barium carbonate, 

 squill, and sodium fluoride. Cats and dogs are very 

 useful, but it is a mistake to assume, as does one 

 port authority, that an excellent sufficiency of cats 

 is a good insurance against rats ; as a matter of ex- 

 perience it is nothing of the kind, for, like practically 

 all domesticated animals, the cat is companionable, 

 and unless it has a spare diet, and is deprived of the 

 association of too many of its kind, it becomes a hunter 

 after the fleshpots of Egypt rather than a menace to 

 rats. Ferrets are useful only in the hands of practical 

 rat - catchers ; for in unskilled hands they get lost. 

 Nevertheless, since they are useful in skilled hands, 

 they may render excellent service to the community 

 when they are associated with a game terrier in an 

 anti-rat club, and such clubs should be a feature in 

 every village and rural town. Gassing, too, has its 

 advantages, sulphur dioxide being perhaps the safest 

 to use, but as a lethal agent it is inferior to chlorpicrin 

 gas. The U.S.A. Government report favourably on a 

 gas called cyanogen-bromide. There is much to be 



NO. 2742, VOL. 109] 



said for the raising of the status of those who are 

 engaged in the war against rats ; for modern drain- 

 age systems, while aiming at efficient sanitation, 

 undoubtedly provide excellent facilities for rat locomo- 

 tion, and tend to defeat the object of rat- weeks by 

 allowing the hard - pressed rats of one district to 

 escape to another district where the rat-week is next 

 week. The vast emporiums, too, provide problems 

 in rat repression which no ordinary rat-catcher can 

 grapple with effectively. To sum up, if rats are to be 

 appreciably diminished in number it is imperative 

 that— 



(i) An International Commission be created to 

 extract the best of all existing rat laws and codify 

 them in such a manner as to ensure their being 

 concurrently effective in all countries, and in all ships 

 and vehicles of water transport. 



(2) Our own rat laws be amended : {a) to make 

 rat trafficking a crime ; (6) to make rat reinfestation 

 a crime ; (c) to make financial provision for the 

 carrying out effectively of the rat law ; and {d) to 

 make it an obligation upon the Ministry charged 

 with the administration of the Act to enforce its 

 being carried out by the authority concerned. 



(3) All bona fide rat-catchers be registered and 

 given instruction in elementary pathology, sanitary 

 engineering and hygiene, and certificates be issued 

 to competent and lionest persons engaged in this 

 business, withdrawable publicly in the Press in the 

 event of petty larceny, offences against the Rats 

 Act, or for other specified reasons. 



(4) The question of the use of virus should be 

 settled, and whatever conclusion is arrived at in this 

 regard be given the widest publicity. 



(5) Twice a year all British authorities be compelled 

 to co-operate and synchronise their efforts in rat 

 destruction, and during the period, public lectures 

 on rat destruction, rat proofing, and the necessity 

 for eliminating possible rat -breeding grounds, be 

 organised by the authorities. 



(6) The authorities responsible for the zoological 

 laboratories of all universities, colleges, and institutes 

 be invited to set apart a portion of their time for the 

 teaching of economic biology in so far as it concerns 

 the rat, the diseases it carries, its movements, the 

 nature and extent of its depredations, its natural 

 enemies, and the known poisons which are safe to 

 use, this with the view of discovering improved 

 methods of ensuring its destruction. 



(7) In all elementary schools pupils be taught the 

 life-history of the rat, regarding the rat as man's 

 natural enemy, the toxicity of the various raticides 

 in common use, the value of the barn owl {Strix 

 Flammea), the ferret, the weasel, the common kestrel, 

 and the pine marten, the use of baits, varnishes, traps, 

 the progress made by gassing as a method of rat 

 destruction in ships and in places where it is possible 

 to confine the gas, and the best methods of destroying 

 rats (by water -flooding) in their runs, an effective 

 method of killing rats in the country. 



(8) All local authorities should frame their bye- 

 laws so as to encourage rat proofing, and all employers 

 of labour should exhibit in canteens, etc., a card, 

 12 in. X 10 in., warning their employees against leaving 

 about the debris of food, and a reminder : " No 



SCRAPS, NO RATS." 



It cannot be urged too strongly that of all remedial 

 measures against the rat, the most important are 

 rat proofing and the withholding of food and water, 

 especially water, for rats can exist much longer 

 without food than without water. 



