Slick, hardpacked runways indicate an old established colony. The sighting of live rats is a sure sign of infestation. Sightings in the daytime indicate large populations, disease or poisoning. Mummified rat carcasses may indicate a former infestation although many fresh carcasses suggest disease or poisoning. Sound - Usually rodent sounds are heard at night or in quiet areas.
Rodents moving at night often scratch, gnaw, and fight.
The young often squeak while in the nest. Any place a pencil can be poked, a mouse can go. Rats can climb the outside of vertical pipes up to 3 inches in diameter and any size if within 3 inches of a wall. Rats can jump vertically 36 inches, horizontally 48 inches, and reach horizontally or vertically 15 inches. Rats can jump 8 feet from a tree to a house if the branch is 15 feet above the roof.