Common Rat

Other Names: Brown Rat, Grey Rat, Norway Rat, House Rat, Wharf Rat, Water Rat, Barn Rat, Sewer Rat, Super Rat
These "super rats" can reach 40cm in length. Each female rat can give birth to 20 pups in her lifetime. Some factors affecting rat populations in cities include continuously mild winters, weather-related disasters, and encroachment of their habitats by new urban development.

  • Facts

  • Identify Damage

  • Control Options

  • Baits


Description of the Common Rat

  • Scientific Name:
    Rattus Norvegicus
  • Colour:
    Usually greyish-brown, but colour varies from a pure grey to a reddish brown; hard to identify by colour alone
  • Weight:
  • Length:
  • Tail Length:
    15-20cm; shorter than the body
  • Body:
    Heavy & thick body, blunt nose
  • Ears:
    Relatively small; close to body
  • Eyes:
    Large & protruding black eyes
  • Lifediv:
    5 to 12 months
  • Droppings:
    2cm long with blunt ends; dark colour; found in groupings

Reproduction of the Common Rat

  • Litter Size:
    8-12 pups per litter
  • No. of Litters:
    4-7 per year
  • Sexual Maturity:
    2-3 months
  • Gestation Period:
    22 days
  • Breeding Season:
    Indoors: All year; Outdoors: Spring & Autumn

Diet of the Common Rat

  • Daily Amount:
  • Daily Water:
  • Daily Food:
    Cereal grains, meats, seeds, cockroaches, fruits, shrimp

Habitat of the Common Rat

  • Geography:
    Throughout Europe
  • Nest Location:
    Burrows in soil, sewers, basements, lower portion of buildings
  • Home Range:
    8-30m from nest
  • Active Periods:
    Nocturnal; most feeding occurs 30 minutes after sunset and before sunrise


Droppings are the most commonly encountered evidence of rodent activity. Even a small rat infestation can produce literally thousands of droppings in a short period of time.

An adult rat typically produces 40 to 50 droppings per day. These faecal pellets are usually dark-coloured, 2cm inch in length, and blunt at both ends.

Gnaw Marks

Evidence of recent gnawing is an excellent sign for determining the presence of Common rats.
Rats tend to gnaw on wooden structures such as corners, floor joists, and wall studs. When Common Rats gnaw holes into cartons and boxes, the holes typically measure about 5cm in diameter and after contain rough, torn edges.

Sounds and Odours

Another indication that rats are present is a strong musty odour. Cats and dogs may excitedly sniff and probe an area where rats or mice are present, and often indicate this by scratching or making unusual sounds.

Control Options

Traps | Rodenticides | Repellents | Prevention

Common rats eat and contaminate food and damage properties by gnawing and burrowing. They spread diseases that affect people and pets.

Below is information on the many rat control options, such as rat repellent, traps, and rodenticides. We also offer prevention tips to help you with rat control, such as rodent proofing your home.

Rap Traps

Rat traps are an effective method of non-toxic rat control. There are 2 types of rat traps commonly used for rodent control: Snap Traps and Electronic Traps.
These mechanical traps provide a quick solution to a rodent control problem and can be used many times. One advantage of rat traps is the ability to “recover” the rat to confirm its elimination.

The most important technique for effective trapping is good trap placement in areas of high rodent activity. The most common trapping mistake is using of too few traps.

Statistics show that more rodents are trapped on the first night than on any other night. For this reason, it is essential to use a large number of traps initially.

Some rats are harder to catch and are Neophobic or “extra cautious” of new objects that suddenly appear in their environment. For these cases, rat traps should be placed out, but left unset and baited for a couple days prior to setting the traps.

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Rodenticides, also known as Rodent Baits, offer an economical and efficient approach for eliminating rat populations. Just as with trapping, it is critical to place rodenticides in the correct location – typically against the wall between their nest and source of food.

Additionally, Baits should be placed into areas that appear to be their favourite locations (evidenced by piles of droppings, shredded paper, tracks, etc.). Because rats travel further to feed than mice, bait should be placed between 5-15m apart.

For best acceptance, place Rodent Baits out during the late afternoon so they will be fresh at dusk when rats become active.

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Ultrasonic rodent repellents are an effective method of controlling rats. High-frequency sound waves are emitted in a non-repetitive pattern to prevent rodents from becoming used to the sound.

For additional effectiveness, the loudest spike in sound replicates the scream of a dominant male rodent. Rodents are very territorial and will constantly fight to establish dominance. The sound of a dominant rodent will discourage others from inhabiting a territory.
It is important to note that ultrasonic frequencies do not travel between walls. So for the most effective rat control, ultrasonic units need to be placed in multiple rooms.

The most common repellent mistake is using them alone to control an established infestation.

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Rodent populations will continue to increase in conditions that allow easy access to food and shelter.

Sanitation efforts in conjunction with rodent proofing provide the best solution to reduce or completely eliminate these conditions.

Two excellent tips are to seal off openings to your home and eliminate their likely food sources. To adequately keep rats out of your home all openings need to be sealed off.

In addition to exclusion, careful storage of foods and elimination of clutter are valuable steps in the fight to control rats. If Norway rats become established in or around your yard, they are usually obtaining food from obvious sources. These include rubbish, outdoor dog pens, vegetable gardens, compost piles, or bird feeders.
And remember, it only requires one poorly managed house or garden for a colony of rats to take over the neighbourhood.

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They spread diseases as they eat and contaminate food. They damage properties by gnawing and burrowing. They can eat nearly any type of food but prefer meat and fresh grain.
Tired of empty rat traps? Bait that is missing? Discover the best rat Bait to use to catch a rat. Get rid of those rats with Victor’s best rat trap Bait suggestions. Suggested Common Rat Baits:

  • Thin slice of hot dog
  • Bacon
  • Peanut butter
  • Dried fruit
  • Chocolate
  • Nesting materials such as dental floss
  • Tying the rat bait to the trigger will prevent the rodent from licking or nibbling the bait and stealing it without setting off the trap. For rat baits that cannot be tied (e.g. peanut butter), it’s best to use small amounts.

Remember, some rats are harder to catch and are neophobic or “extra cautious” of new objects that suddenly appear in their environment. Some rats can be extra cautious so leave an unset rat trap out for a few days before setting it with rat trap bait. This will give the rat a chance to become accustomed to it and to be caught by it.