Entry Points

These rats have no problem reaching almost any area of the house, so many homeowners struggle to keep these pests out. These rodents often enter homes from:

• Chewing entry holes

• Damaged vent covers

• Gaps in shingles

• Squeezing through cracks

• Chewing on electrical wires

• Damaging furniture and storage boxes

• Ripping up insulation

Diseases

Roof rats spread diseases like salmonellosis through pantry foods contaminated with their droppings. These rats can also transmit rat bite fever through bacteria in their mouth. Trichinosis may be contracted through eating undercooked meat of animals that have fed on rats. Rats contaminating food or food preparation surfaces can transmit food poisoning.

Roof rats are the principle reservoir of plague throughout the world. Historically, infected fleas have transmitted serious plagues from rats to humans. Bubonic plague was a scourge in Europe several times throughout history. There are still outbreaks of plague in the United States and around the world today.

Hantavirus

Hantavirus pulmonary syndrome is transferred via inhalation of:

• Droppings

• Rodent urine

• Saliva

How Do They Transfer Diseases?

Common ways roof rats transmit diseases are from:

• Bites

• Contamination

• Droppings

• Fleas that feed on the rodents

• Physical contact

Droppings are a good indicator of roof rat activity. Their droppings are 12 to 13 mm with pointed ends, whereas Norway rat droppings are 18 to 20 mm and capsule shaped.

Grease Marks

Grease marks along surfaces can be signs of an infestation. Grease marks are produced as the rodent travels along an edge, and the oils in their fur are deposited.

Visual Sightings

Sightings of live or dead rodents indicate rodent activity. If roof rats are seen exposed, it often indicates their hiding spaces are all filled by other rats or that they have been disturbed, such as by construction. You can find indoor nests constructed in insulation area including attics.