MIGRATION OF RATS.

Oamaru Mail, Volume XXXVII, Issue 10243, 4 September 1909, Page 4 (Supplement)

MIGRATION OF RATS.

In nearly all countries a seasonal movement' of rats from houses and

1 barns to the open fields occurs in spring, " and the return movement takes place as » cold weather approaches. The move- " ment is noticeable even in large cities. s More general movements of rats of--7 ten occur. In 1903 a multitude of migrating rats spread over several " counties of Western Illinois, U.S.A. I For several years prior to this invasion no abnormal numbers were seen, 1 and their coming was roinarkatl.y, sud- ' den. An eye-witness to the pheno--5 menon informed the writer that as he 1 was returning to his home by moon--5 light he heard a general rustling in 2 the field near by, and soon a vast army 2 of rats crossed the road in front of him, all going in one direction. The mass 3 stretched away as far as could be seen I in the dim light. These animals rcJ mained on the farms and in the villages " of the surrounding country, and during 1 the winter and summer of 1904 wero a veritable plague. A local newspaper | stated that between March 20 and April 20. 1904, a farmer killed 3435 rats on ' his farm. He caught most of them in ' traps. In 1877 a similar migration occurred ' into parts of Saline and Lafayette coun- ! ties, Mo., and in 1904 another came ■ under the writer's observation in Kansas Kiver Valley. This valley for the most part was flooded by the great ' freshet of June, 1903, and for about ten days was covered with several feet '. of water. It is certain that most of ; the rats in the valley perished in this flood. In the fall of 1903 much of the [ district was visited by hordes of rats, 1 which remained during the winter, and by the following spring had so increased in numbers that serious losses of grain 1 and poultry resulted. No doubt the majority of the so-called migrations Of rodents are in reality instances of unusual reproduction or of enforced migration owing to lack of food. In England a general movement of rats inland from the coast occurs every October. This is closely connected with the closing of the herring season. During the fishing the rodents swarm to the coast,- attracted by the offal left from cleaning the herrings, and when this food supply fails they hasten back to the farms and villages. In South America periodic plagues of rats have taken place •in Parana, Brazil, at intervals of about thirty years, and in Chile at intervals of from fifteen to twenty-five years. These plagues in the culitvated lands follow tho ripening and decay of the dominant species of bamboo in each country. The ripening of the seed furnishes for two or more years a favorite food of rats in the forests, where the animals multiply greatly; when this food fails they ;:.• forced to the cultivated districts subsistence. In 1878 almost the entire crops of corn, rice, and mandioca in the State of Parana were destroyed by rats, causing a serious famine. An invasion of black rats in the Bermuda Islands occurred about the- year I 1615. In a space of two years they had increased so alarmingly that none of the islands was free from them. The rodents,- devoured everything, which j came in their way—fruit, plants, and , even trees —so that for two years the ; people were destitute of bread. A law .. was passed requiring every man in the , islands to set twelve traps. In spite j of all efforts the animals increased, mi- E til they finally disappeared, with a sud- J denness which could have resulted only ] from a pestilence. £