Rats: why it is impossible to get rid of them?
All people are divided into two unequal groups concerning rats: the most part does not love them, and smaller - just idolizes. Rats live near the person many centuries. What secret is hidden in these animals? Why they cause such polar feelings in people? Give we will understand it.
Life of rats on nuclear test sitechose by
of the USA islands of the atoll Enivetok located in the western part of the Pacific Ocean as the ground for test of the nuclear weapon. The population of islands was evacuated. And during the period from 1948 to 1958 about 40 explosions were made there. Fiery tornadoes destroyed all live on the way. Huge mushrooms radiated killing radiation.
At the end of 70 - x years of the USA sent troops to Enivetok to carry out disinfecting of islands. The infected soil and construction debris were buried in a burial ground which was closed by a thick-walled concrete construction.
In several years after the end of nuclear tests of the island scientists among whom there were also biologists visited. The high-level radioactivity was noted in the soil, vegetation, and also in the sea invertebrates and fishes living about coral reeves. On one of islands which was damaged during explosions less than others biologists just in case established traps to look whether somebody survived in this hell. What surprise of scientists when they found out that all traps were filled by rats was.
Rodents looked slightly more largely than the relatives whom radiation did not concern. Further research of rats from the atoll Enivetok showed, as duration of their life was considerable above average. Biologists drew a conclusion that the raised radiation did not make any negative impact on rats, and it is rather on the contrary - promoted increase in the size of a body and life expectancy.
If for the ordinary person the fact that rats survived after atomic explosions, is something outstanding, then for the experts who are engaged in studying of biology of rats it is one more proof that rats can easily adapt to life in any extreme conditions, including also the raised radiation.
the Grey rat , or pasyuk (Rattus norvegicus ), - a mammal of a genus of rats, group of rodents. It is a sinantropny look - the cosmopolitan, he lives near the person many millennia and widely inhabits all continents, except for Antarctica and subpolar areas. Practically all Russia is inhabited by these rodents.
Animals quite large, length of a body can reach 40 cm, plus a tail to 20 cm. Weight fluctuates from 150 to 500 grams. Gray rats are omnivorous, have a high intelligence, well remember a route of the movement, adapted to life about housing of the person and in it. In big cities of a rat about 9 - 10 floors can rise, but the main habitat in houses are cellars and first floors where it is possible to find food and household waste. On refuse chutes of a rat can vertically move from the first to the last floor.
Rodents are especially active in a night-time. They prefer to form colonies number in several honeycombs of individuals. The active zone of colonial possession makes 2-3 thousand m 2 . Rats are very mobile and run 10-15 km a day. They are great swimmers, and there can be three days in water without any harm for themselves.
Gray rats are very prolific, in town houses they breed all the year round. The female copulates with several males, pregnancy continues three weeks, it brings from 3 to 20 infant rats into world. In a day the field of genus of a female begin to copulate again. Good food supply (proximity of a garbage can, house refuse chute, food waste which residents scatter near the house) - remarkable incentive for increase of fertility of rodents. If infant rats are born dead or weak, adult rats eat them. Young females begin to breed at the age of 6-9 months.
Life expectancy of a gray rat makes 1,5-3 years. This look is in a stage of evolutionary blossoming. It is considered that rats on Earth are 2-3 times more, than people. In the large cities their number is comparable to the number of the population.
The gray rat is a messenger more than 20 dangerous infectious bolezny, about a half of them are dangerous to the person. Among them - icteric leptospirosis, kriptosporidioz, sypny typhus, plague and some other. Rats are a source of infection with salmonellosis and helminths among which the tapeworm who can fine spoil human life is especially dangerous.
the Room doggie of a devilbegan to call
at the beginning of the 19th century of rats “a room doggie of a devil“. There is in this name a share of admiration of rat talents. Possibly, much of you know that the rat is capable to get through in the smallest crack, to gnaw through shlakobeton and lead pipes. The posterity of one rat with children, grandsons and great-grandsons in a year can reach 15 thousand individuals!
The vigorous activity against the person of a rat deserved it hatred. Already ancient Egyptians began to look for poison to get rid of these persuasive satellites. For many centuries of fight against rats of people tried any smart traps from simple loops - strangleholds to tiny guillotines. People tried to flood and set fire to holes of rodents, smoked them by means of specially prepared mixes, killed with current. Attempt to remove the improved breed of cats was made. Some with despair burned the houses. But all this was useless. Till this moment of a rat are persistent companions of the person.
How people are at war with rats? About it the speech in the following article will go.