Three tree squirrel species are found in Calgary. However, the Eastern Grey Squirrel remains the most dominant. Despite its name, the rodents can have brown, black or grey fur. They not only nest in trees but also enjoy the security and warmth found in attics and chimneys, waking homeowners in early morning hours when they become active, running in the ceiling above the homeowners bedroom. Their extremely dense nests are commonly constructed using branches, leaves, moss and other soft scavenged materials. Outdoors, the nests may block gutters or present a fire hazard in chimneys. When invading indoor spaces, home and building owners must contend with the odor and disease ridden urine and fecal matter. Like all rodents, they have a continual need to chew, which prevents excessive front teeth growth. They are fully capable of gnawing through aluminum, insulation, plastic, shingles, vents, wiring or wood to gain entrance into a building. In damaging plumbing and wiring, the property is then at risk for flooding, fires or accidental electrocutions.