Rats are larger than mice and usually have scaly, naked tails. There are several species of rats.
The brown rat is about 20 cm. with a tail of almost equal length. These rats originated in central Asia. Now they have spread throughout the world. Thanks to ships which transported them to all corners of the world.
The black rat, responsible for plagues, smaller than brown rat. It has, however, larger ears, a longer nose and a pointed snout. They do not interbreed with brown rats.
The pack rat or wood rat is common through out north America. There are about 7 different species of this kind. Their dens are made of partly eaten plants, dung and miscellaneous objects.
Rats have a very flexible body and can squeeze in through tiny holes, climb vertical surfaces, burrow the earth, jump as high as 1 metre and jump down from a height of 15 metre. They can swim at least a mile and can chew through live electrical cables. They can kill another animal which is twice their size. Rats seem to be very intelligent. They are awfully cautious, wary and shrewd.
Great damage is done to property by rats as they grow through them. Rats pillage tons of food grains stored in the granaries. They devour potatoes, bananas, carrots and other produce in the fields. It is very good excellent to eradicate the rat menace as they multiply very quickly. A female rat can reproduce and have at least 15,000 descendants in a year.
It seems rats have only useful quality in them that is of value to man. They are excellent animals for the research laboratory where new drugs can be tested on them. Rats being tough, versatile, quick reproducers and having ability to eat anything are the favorite animals for experimentation.
