Roof rats (also known as black rats and ship rats) get their name from their instinct to find shelter in the uppermost structures of a building. They can reach high areas because they are very agile climbers. For this reason, they may often live in attics or trees, and frequently enter buildings from the roof. So, when you hear a rat scurrying on your ceiling, it could very well be roof rat.
Roof rats are smaller than Norway rats, they are long and thin, have large eyes and ears, a pointed nose, and a scaly tail. Their coats are sleek and smooth with a charcoal grey, black or light brown on top and cream or white along the underside.
Adult roof rats measure 16-20 cm, including their head and body length. Their tails are distinctly longer than their heads and bodies, measuring 19-25 cm. This means that roof rats can measure more than 40 cm long. They usually weigh 150-250 g, but can grow up to 340 g.
The easiest way to identify Roof Rats from Norway Rats is to pull the tail back over the body. That tail of the Roof Rat will reach the nose, while the tail of the Norway Rat will only reach to the ears.
Roof Rats can survive nine to 12 months in the wild. They give birth to about 5 to 8 pups after a gestation period of 21 to 23 days and can have up to 4 litters a year. Newborn rats may reach independence and reproductive maturity at about 3 months. Peak breeding season for the Roof Rat typically takes place in Spring and Fall.
There are many key indicators of a roof rat infestation in the home. First and foremost, seeing an actual rodent, dead or alive. Other signs include:
- Droppings- Rat droppings are long and cylindrical, measuring 12-13 mm. Fresh roof rat droppings are soft and moist, whereas old droppings are hard and dried
- Tracks- Roof Rats and Norway Rats leave a hind foot track of about 1.9-2,5 cm. A mouse’s tracks will be much shorter. Rats will also drag their tails, leaving a mark between their feet tracks.
- Gnawing holes- Gnawing holes from rats are about 5.08 cm or more in diameter and will have rough edges. They prefer gnawing on wood but may also damage electrical wiring
- Noises in the attic or house walls and damaged electrical wires.
To prevent a roof rat infestation, seal up any holes or cracks larger than 2.4 cm with silicone caulk and ensure that all windows and vents are screened. Keep trees and bushes trimmed away from the building and cut back branches overhanging the roof. Roof rats are drawn to any available food sources, so clean up fruit that may fall from trees and keep garbage in tightly covered bins. Be sure to store pet food and other dry food in sealed containers.
Article source: National Pest Management Association, PMP (Pest management professional) & DoMyOwn.