There are two main types of rats in the Tri-Cities: Norway rats and roof rats. While the two have different characteristics, the damage control and prevention methods are the same.

Norway Rat (Rattus norvegicus)

Appearance
the Norway rat is larger than the roof rat. Its body length is 6-8 inches long can weigh an average of one pound (454 g). Its fur is coarse and usually brownish or reddish gray above and whitish gray on the belly.  The nose is blunt and the ears are small, close set and do not reach the eyes when pulled down.

The Norway rat's tail is shorter than the head and body. When distinguishing the Norway rat from the roof rat, pull the tail back over the body. The tail of the roof rat will reach the nose. The tail of the Norway rat will not reach beyond the ears.

Habitat
Norway rats burrow to make nests under buildings and other structures, beneath concrete slabs, along stream banks, around ponds, in garbage dumps, and at other locations where suitable food, water, and shelter are present. On farms they may inhabit barns, granaries, livestock buildings, silos, and kennels.

Although they can climb, Norway rats tend to inhabit the lower floors of multi-story buildings.

Food Habits
Norway rats will eat nearly any type of food, but if given a choice they select a nutritionally balanced diet, choosing fresh, wholesome items over stale or contaminated foods. They prefer cereal grains, meats and fish, nut, and some types of fruit.

Rats require 30 ml of water daily when feeding on dry foods but need less when moist foods are available.

General Biology, Reproduction and Behaviour 
Norway rats are primarily active at night. They usually become active about dusk, when they begin to seek food and water. Some individuals may be active during daylight hours when the rat population is high, when disturbed (weather change, construction, etc.) or when their food source is threatened.

In urban areas most rats remain around the buildings and in yards which provide their necessities, and unless they are disturbed, they do not move great distances.

Female Norway rats may come into heat every four or five days, and they may mate within a day after a litter is born. The average female rat has four to six litters per year and may successfully wean 20 or more offspring annually.


Roof Rat (Rattus rattus)

Appearance
The roof rat is a medium sized rat weighing 150-250g, and measuring about 41 cm in total length from its nose to the end of its tail. The roof rat can be compared with the larger, robust Norway rat which has shorter ears, a blunt snout, and a shorter tail. The general appearance of the roof rat is a black with a grayish belly.

Habitat
Roof rats often will live in trees or on vine-covered fences. Landscaped residential or industrial areas provide good habitat, as does vegetation.

Being agile climbers, roof rats frequently enter buildings from the roof or accesses near utility lines, which they use to travel from area to area.

Feeding Habits
The food habits of roof rats resemble those of tree squirrels, since they both like a wide variety of fruit and nuts. They will feed on most anything if necessary.

General Biology, Reproduction and Behaviour
The number of litters depends on the area and varies with proximity to the limit of the climatic range, availability of nutritious food, density of the local rat population, and the age of the rat. Typically, three or more litters are produced annually. The peaks in breeding usually occur in the spring or the fall. Litters include five to eight young, which develop rapidly.

Damage Prevention and Control Methods

Exclusion

• Seal all openings that provide entry to structures (e.g. drains, vents and crevices in foundation).
• Garage doors must be flush to the ground.
• Inspect your basement and house for cracks and holes.

Habitat modification and sanitation

• Do not to disturb their original habitat until they are under control, or they may run to another area. 
• Store garbage in metal containers with tight lids.
• Bird feeders attract rats. Use rodent-proof bird feeders and sweep up all fallen bird seed.
• Place trash outside shortly before pickup; don't leave plastic garbage bags out overnight.
• Make sure the BBQ is cleaned well after every use
• Remove weeds and debris near buildings and in yards; don't give rats a place to hide.
• Store opened food in metal or glass containers with tight lids.
• Don't leave extra pet food out; store it in a secure container.
• Sweep up food remains, litter, and trash inside and outside your home.
• Make sure you have screens on windows; inspect windows and screens for holes.
• Keep outside doors closed; use metal trim to prevent rodents from gnawing and entering underneath.
• Don't provide hiding places for rodents; store materials such as lumber and boxes on a rack with a clean, open area underneath. Get rid of unused materials and junk.
• Reduce vegetative cover (for example, trim vines from buildings and fences).

Trapping
Snap traps, live traps and glue boards can be used.

Poison baits (rodenticides)
Baits are available in several forms. They may be useful in some situations, however extreme care must be taken when using this type of rodent control. Please call us at 604-927-5447 for more information.