If you suspect that rats are romping about in your home, immediate action is required. Rodents are among the most dangerous health and hygiene pests. The animals themselves and their droppings transmit pathogens, bring in parasites, contaminate food supplies and destroy furniture. Since living animals can only be seen extremely rarely, even with high infestation pressure, it is important to identify other symptoms. The primary focus is on the excrement, as a clear indication of the presence of the pests. Just wondering what does rat droppings look like? We have compiled all important information about size and smell for you here.


  • Rodent genus within the Old World mice (Murinae)
  • More than 60 species worldwide
  • Most common species in Central Europe: black rat (Rattus rattus) and brown rat (Rattus norvegicus)
  • Domestic rat: head-body length 25 cm plus tail length 25 cm, weight 400 g
  • Brown rat: head-body length 30 cm plus tail length 23 cm, weight 550 g
  • House, soil or tree-dwelling pests
  • Explosive reproduction with 6-8 litters per year, each with 8-22 young
  • Dangerous health, hygiene, food and material pests

While the population of the black rat is declining in Germany, the larger brown rat continues to spread unabated. Both rat species specifically seek proximity to humans, with the brown rat also staying in the sewage system, on and in trees and in ditches within the garden.

rat feces

The most striking evidence of an infestation with the pests is rat droppings. Black rats produce banana-shaped, rather narrow, dark brown excrement. In adult animals, the size moves between 1 and 2 cm. These are usually scattered over a wide area in the house. Brown rats droppings, on the other hand, are spindle-shaped, broad, and black. With a size of 2 to 3 cm, these excrements are slightly larger. The small accumulations of solution are characteristic.

In order to be able to assess whether there is actually an acute need for action, you cannot avoid taking a closer look at the excrement. Fresh rat droppings are soft and shiny. Old legacies from the pests, on the other hand, are either rock-hard if they have been dry or moldy if the air humidity is high. Therefore, take a piece of wood and press it onto the edge of the solution. If the droppings can be punctured, the rats have already migrated. If the material sticks to the wood chip, countermeasures should be initiated promptly. If there are small and larger fresh pieces of droppings, this circumstance indicates active reproduction activity and the presence of young animals. In view of this warning sign, we advise immediate countermeasures.


If rats have nested in the house, an unmistakable smell spreads. This does not come directly from the excrement, but rather from the urine. In addition, the animals have special glands with which they emit the unpleasant smell to mark their territory. If there is a strong smell of ammonia in your home environment, all alarm bells should ring, because this symptom indicates a high infestation pressure.

Tip: Smear marks are another indication of the presence of rats in the house. Since the animals always use the same routes, they leave curved tracks of body fat, dirt and dust in the house, on the attic or on the balcony.

Removal of faeces and odor

Rats are credited with spreading more than 70 diseases. The faeces – next to the animal itself – plays a central role. It is the dust in particular that needs to be treated with caution. It may contain the dreaded hantavirus that is inhaled. In addition, the smell of ammonia pollutes the whole house. How to clean:

  • Put on a dust mask and rubber gloves
  • Ventilate all rooms well
  • Clean up rat droppings with a broom, hand broom and shovel
  • Remove from corners with a vacuum cleaner
  • Wipe all surfaces with chlorine bleach or disinfectant; leave on for 20 minutes beforehand
  • Wipe off with water and normal detergent
  • Clean bed linen, tablecloths, curtains and other fabrics in the washing machine

Depending on the intensity of the odor, repeated cleaning with chlorine bleach may be necessary. Finally, a long shower removes all dust residue from the hair. The gloves are not used again, but end up in the garbage can.

Differences from other excrement

In addition to rats, other animals have developed into cultural successors of humans in order to nest in houses and attics. Although not always welcome, these animals do not pose an immediate health threat like brown rats and brown rats. Since the excrement looks the same at first glance, we have put together the main distinguishing features for you:

  • Mouse droppings: 3-7 mm long, fusiform or circular, laid out in dropping packets in close proximity to the nest
  • Stone marten droppings: 8-10 cm long, 1-2 cm thick, elongated
  • Bat droppings: resembles chocolate sprinkles and can be found on window sills, on the floor, or stuck to walls
  • Dormouse droppings: 5-10 cm long, twisted and with a penetrating smell

In addition, in recent years, raccoons have discovered the comforts of human habitation. From 2 specimens that were released in Germany in 1934, a population of several 100,000 animals has developed. Since the omnivores really eat or nibble on everything, they are not welcome as material pests. The excrement differs significantly from rat droppings in terms of volume and is more like the droppings of small dogs.

Tips for preventing a rat infestation

To prevent the dangerous pests from settling in your house in the first place, it is enough to observe a few simple preventive measures. The focus is on the handling of food supplies, supplemented by regular checks. How to do it right:

  • Stock up only as much as is needed in the short and medium term
  • Pack food tightly and do not store openly
  • Dispose of expired and spoiled food immediately
  • Don’t leave leftovers lying around
  • Empty the kitchen trash can at least once a day
  • Close garbage cans tightly
  • Empty and rinse pets’ food bowls immediately after meals
  • Carefully close any cracks and crevices in the house as possible access points
  • Before airing the ground floor, put away open food
  • Regularly check all niches and corners for rat droppings
  • Check furniture and cables for signs of gnawing

Equip your toilets with backflow flaps, which prevents brown rats from entering the sewers. In addition, any damage to the sewer system should be repaired promptly, as these are places where rats can easily enter. As soon as winter sets in, house and brown rats seek even more targeted access to the house, since the rodents like it warm. Therefore, point out to all family members that the doors must be closed quickly. Furthermore, cellar windows without bars should not be left open for long periods of time.

Do not allow rats in the house, because the rodents pose health and material hazards. As soon as you suspect that house or brown rats are in your home environment, their excrement acts as proof of the actual presence. With increasing infestation pressure, an intense smell of ammonia spreads through the house.

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *