Food and warmth are the main attractions for rats. Eliminating food sources and sealing off entrances to warm homes and other structures can help to drive down rat populations.
Rats can live on just an ounce of food and water each day, so when food is bountiful, they will make themselves at home. Rats are attracted to homes, businesses and restaurants, and they will feed from the trash if it is left uncovered or if they can gnaw through a receptacle to gain entrance.
Signs that rats have invaded a home or business include gnawing and scurrying sounds in the attic or walls, as well as chewed spots, wood chips, wood shavings and tooth marks in baseboards, windows, doors, electrical cords or even packaged foods. Droppings are also a definitive sign of a rat infestation.
Although rats can grow quite large, they are flexible and can fit through very small openings, including holes and cracks in foundations or walls, even if the opening is as small as a dime. They also enter through vents, open windows and grates. Even openings that are made for wires and pipes in the foundation of a home can give rats access.
Some homeowners and business owners have success with setting traps for rats or putting rat poison out. Others find that hiring a professional exterminator is a better option, since rats can die inside walls or other inaccessible areas of a structure, leaving an unpleasant smell behind.