Black rat

Le 12 March 2020

The black rat, attic rat or field rat

Le rat noir, rat des greniers ou rat des champs

The black rat has a coat that goes from black to hazelnut with the underbody lighter. It generally reaches a length of 15 to 20 cm, to which is added a long tail of 20 cm always longer than the body

In adulthood, this rodent can weigh between 70 and 300 g. Compared to the brown rat, it is a poor swimmer, but a much better climber who rather seeks to flee from above.


Portée de rats

Under good conditions, it can reproduce throughout the year, the rats having 3 to 6 litters per year counting up to 10 pups each. Gestation lasts 21 to 29 days. Litters go up to 5 per year, each litter ranging from 6 to 16 young.

They will be sexually mature within 3 months.

The black rat can live up to 3 or 4 years, in social groups which can reach up to 60 individuals.


It is a nocturnal and omnivorous animal. It is very wary, more than the brown rat, and can take a long time before consuming new food. If an individual is in poor health after consuming a new food, the dominant male can urinate on it so that no other fellow man consumes it.

The nests of black rats are generally located high up, in the dry parts as well as in the dark and very quiet corners of buildings. Hence its nickname of attic rat, unlike brown rats (brown rats) that hide in the lower parts of buildings or in galleries on the ground.

Sensory perceptions

Smell is the predominant sense. It is by their smell that the rat recognizes its congeners, its territory by the smell of its urine, it can find a way if it marked it with its urine. Smell is also essential for foraging.

Hearing also plays an important social role. Rats communicate with a wide variety of sounds, including ultrasound. Bass sounds tend to calm him down, while high, loud sounds get his attention more and sometimes stress him out.

The rat has a poor perception of space and rather relies on its sense of smell and hearing to interact with its environment.

How to prevent an outbreak of black rats in your home?

Black rats can easily sneak through cracks, even small ones. To avoid a rush of black rats in your buildings, it is necessary, at first glance, to plug all possible openings of the dwellings.

Then you have to:

  • Always close your garbage cans tightly,
  • Clean them regularly,
  • Hide all foods well to protect them from rats,
  • Avoid the open compost piles that are easily made next to houses,
  • Close behind you when going through a door. (Especially when it comes to the attic),
  • Patch cracks in foundations,
  • Eliminate any space suitable for their nesting

Rats have a highly developed sense of smell that allows them to avoid the traps set up by humans. They communicate with ultrasound whose frequency is too high to be audible to the human ear. As soon as they sense danger, they warn the other rats.