To begin eliminating your rodent problems, start with a good inspection. Inspecting your home, shed or barn is important for determining which type of rodents are present: rats or mice. A good inspection provides three main valuable pieces of information:
Runways are usually evident in rodent infestations because rodents repeatedly use the same pathways between their nests and food sources.
Common linear pathways include foundation or sill ledges, tree branches, electrical lines, pipes and sewer lines.
Mice typically travel 6-30 feet from their nests to a food source. Rats are more adventurous and will venture out 25-100 feet from burrows.
These grease marks are created from oil and dirt on the rodent's skin and often appear along wall areas next to runways.