Rats must gnaw on hard objects to cut back their constantly growing incisor teeth. Rats live in the most unsanitary places, and are carriers of serious health risks to humans from their droppings. Rats can even use urine trails to find their way in the dark.

Rats and mice often become a serious problem in cold winter months when they seek food and warmth inside residential and commercial buildings. Rats may suddenly appear in large numbers when excavation work disturbs their in-ground nesting areas, or if their food source is changed.  Rats are commonly a problem when a building is located near waterways, creeks, canals, or other places where a water source is available.