RAT AND FLEA PROBLEM.

Auckland Star, Volume LIV, Issue 219, 13 September 1923, Page 8

RAT AND FLEA PROBLEM.

THE ORIGIN OF PLAGUE. METHODS OF CONTROL. EXTERMINATION IMPOSSIBLE. Pome interesting facts regarding the steps taken to combat the spread of plague in Sydney, and also the most effective methods of freeing cities from rats and fleas, were contained in a lecture of Dr. J. S. Purdy, the distinguished Metropolitan Medical Officer of Health at Sydney, rend to the Auckland Centra of the New Zealand Sanitary Inspectors' Association, last evening liv Dr. O. fie (live Lowe. Mr. H. Paul],*president of j the centre, occupied the chair. The lecture stated that the first point of attack in outbreaks of plague was the waterfront, then the warehouses in the rear of the wharves. Past experience in several large cities where attempts had been made at the wholesale extermina- j tion of rats had proved that the attain- j ment of such a desirable objective was j impossible owing to the prolific breeding ■ habits of rodents. Thus the fact that a | female rat might rear five litters, each ! with as many as eight young, in a year, \ and that assuming theoretically an ! equality in the number of the sexes in a litter, there could be 080 progeny from j one pair of rats in nine months, showed ', that by all known hitherto well-tried j methods of poisoning, trapping and rat- j proofing it was beyond reasonable possibility absolutely to wipe out the rat. The cunning of the rat was proverbial, j being thp "knowingest varmint of any , we have." As a matter of fact, the prey j matter of the brown rat's brain was i highly developed, which accounted for j his hijjh rate of intelligence, his alertness, his memory, and other eharaeteris- I tics, which, apart from his fecundity. | made him so formidable an enemy to exterminate. RATS WARY OF TRAP?. Rats, being intensely cunning, became wary of traps, and a certain proportion 'of rats speedily became trap-shy just as 'they became shy of poison baits, and \ lit was necessary to use much ingenuity i and a variety "of traps to circumvent them. A cheap, ordinary break-back spring trap in the right hands, and set | correctly, might account for large numbers of rats, when systematically cleaned I and used, whilst an expensive French wire trap unless skilfully set would j prove a "dud." As rats had a very keen ! sense of smell the trap must be handled ! as little as possible in setting. % the . trapper wearing gloves, smearing bis , hands with oil of rhodium or aniseed, or well rubbing them with earth. After explaining the merits and demerits of baits of various kinds. Dr. I Purdy'e lecture referred to the method of attempting to destroy rats by introducing an infectious disease in them by culture of microbes. But this had not proved effective owing to the rats ar-quir-ing immunity. Plague itself, probably the most fatal disease known among rats, never succeeded in exterminating them in a given district, and therefore the outlook in this particular direction did not appear very hopeful. TRANSMITTER? OF PLAGUE GERMS. Plague was primarily a rat pestilence and it could only affect man in a | secondary manner fay ibeins spread hy j (leas. In Australia and New Zealand, i apart from rats, the presence of fleas iin houses was due to the keeping of flea-infested dogs and, in some cases, eats. Fleas naturally lived upon the animals which they infested, or upon man. The eggs laid by the Ilea miglit fall on the floor or the carpets of houses, and. after hatching, live for an indefinite ; period upon the dust accumulations 'under i-arpets and in c?-vices and joints ill the flooring. Thus, to set rid of fleas, attention should first be directed to any [domeath- pets, which should be treated by rubbing them either with kerosene nii.xod with three parts of some ordinary oil. such as linseed oil. to reduce the strength, or by some other pulkide. Some remarks on the recent outbreak in Sydney were included in Dr. PnrdVe j lecture, showing that the measures taken j !to make produce premises rat-proof i proved to have been the best insurance | [against plague, and that the cyaniding | of any infected premises was the most I I effective means of killing both rats and j |lleas. Water supplies must all be shut] off from rats, and the only safe method of disposing of garbage in an urban area was by incineration. Whilst it was impossible to exterminate the rat. it was poss'ile to build him out, and to kee;> j down his numbers by i-onstaut trapping | land poisoniusr. The Hodier method of j I killing tlie females ami releasing the | 1 maltfs. and so by sexual repression | ultimately exterminating rats was not I believed to be practicable in a large , city. Fumigation with hydrochloric acid was the most effective means of killing rats ani fleas, and kerosene emulsion j was advocated a-i the most effective J practical application for killing U-.-as. PETS AND BAB IKS. ! At the close of his le-.utre. Dr. de i dive I.owe made reference to the para- | I graph which appeared in the "St.ir. in ;the section devoted to vVomen's World.] I evidently from lV pen of ■some fair] j correspondent with the peti-nnnip ot - I Shirley. In it the writer referred to jdogs. cats, and babies, attributing to the j I doctor the statement that some women j preferred the animal pets to lia'iics. T.'.e .doctor said that, he made !>■■ reference !to babies in his Ifntnrr. nor d:J he mean |to insinuate what wa< evidently sei;-.ed 'upon by the lady writer as a comparison ! between women's love of dogs and 'barbies. "Tlie Zoo," re said, "is e<sentiI ally a pliie for animals, and. sm-n. J one expects to find the He;> present 'there: hut not in one's house." Tlir i doctor quite agreed with the writer oi j the paragraph in Women's World, in I which plie stated: "We haven't any logic." If the paragraph ;ie rcferrol to ; was a sample of women's logic, tiien ! Shirley nj- right. '"They Invcn't any."