What is Rodent / Mice / Rats and why Rat Fumigation is necessary for the House?

Rats and mice are very destructive and contaminate buildings. Rats and mice urinate often, creating stains and offensive odors. A single rodent will produce about 25,000 feces droppings in a year.  They also do damage to electrical wiring by chewing off the insulation. It is estimated that 25{23820674f91ec36f5ca9b0d7ffbb29e72142de4d9260de4131e0701e1e8a0f40} of fires, of an unknown origin, are caused by rats.

Facts
Rats and mice live off man and give nothing beneficial in return.  They spread disease, damage structures and contaminate food. Rats damage one-fifth of the world’s food crop each year. The real damage is in contamination. One pair of rats shed more than one million body hairs each year and a single rat leaves 25,000 droppings in a year. They transmit many diseases, including: Murine typhus fever, rat bite fever, salmonellas or bacterial food poisoning, viral diseases such as foot-and-mouth disease, and many other diseases.  Norway rats can also carry the rabies virus.   Fleas from infected rats can also transmit the plague.  Rodent feces are the cause for the fatal Hantavirus.  The Hantavirus has been found locally in mice droppings. Rats memorize their environment by body and muscle movement alone. When objects are removed from their territory, rats will continue to move around them as if the objects where still there.  They are highly suspicious of new items in their environment. This is important to know when treating for rodent infestations. Successful control depends on proper identification of the different species. Norway and roof rats differ in size, habits, food preferences and regions. Techniques that eliminate one species may not eliminate the other.
Rats visit fewer food sites than mice. However, rats eat much more at each site than mice.

Signs of Rat & Mice infestation

Rats and mice constantly leave droppings. Fresh droppings are dark in color and soft in texture, but after three days they harden and lose the dark color. Rats always travel the same runways and leave “smudge marks”, a buildup of dirt and oil from their fur; along walls, pipes, gnawed openings, beams, and rafters.
Rats keep runways free of cobwebs, debris and dust. Outside, runways appear as narrow paths through vegetation.
Rats and mice make sounds when climbing, clawing and moving.
Footprints and tail drags can be seen in dusty locations.
Gnaw marks are a sure sign of rats and mice.
If dogs or cats unexplainably get excited, rodents are probably moving about in wall voids or ceilings.