Rats and mice produce many droppings. Mice will produce up to 80 a day. It is often these droppings that are the first sign of an infestation of rats or mice. It is possible to identify the species from the appearance of the droppings.
Identify the problem
- There are four species of pest rodent in New Zealand. The mouse (Mus musculus) and rats; the Roof Rat (Rattus rattus) also known as the Ship Rat and Black Rat, the Norway Rat (Rattus norvegicus) also known as the Water Rat, and the Kiore (Rattus exulans) also known as the Pacific Rat.
- You are unlikely to be able to examine the rodent closely and it is often only the evidence of droppings that you have to identify your infestation. The size and shape of these dropping can be a good indication of what rodent you have. The image below may help you identify the rodent from the dropping you find.
- The main difference between the droppings of the three common rodent pests is size. Mice droppings are small (4-7mm), rat droppings are larger, roof rats (7-14mm) and Norway rats (14-19mm). They also differ in the shape of the end of the droppings; Norway rat droppings are rounded while mice and roof rat droppings are pointed.
- Note that droppings change a little as they dry out. If the droppings are soft and moist this suggests that they are recent and suggest active infestation.
- Other signs of rodents include hearing noises from the roof void or walls. There may be other causes. Read this article for help in identifying the cause of such sounds.
Did You Know
Rodents (rats and mice) produce droppings and urine almost continually. Mice will produce up to 80 droppings per day and constantly dribble urine. If an infestion is left to become established a strong musty odour will build up. This odour is an indiction of a large infestation that has been present for some time.
Rodent pests (rats and mice) in New Zealand carry and transmit disease to humans. The transmission of disease from animals to humans is known as zoonosis.
Leptospirosis: Leptospira interrogans
In humans, Leptospirosis (aka Weil's disease) can cause a wide range of symptoms, including:
- High fever
- Muscle aches
- Jaundice (yellow skin and eyes)
- Red eyes
- Abdominal Pain
Many of these symptoms can be mistaken for other diseases. In addition, some infected persons may have no symptoms at all.
How the disease spreads:
- Eating food or drinking water contaminated with urine from infected animals
- Contact through the skin or mucous membranes (such as inside the nose) with water or soil that is contaminated with the urine from infected animals
Salmonellosis: Salmonella typhimurium and Salmonella bovis-morblficans
- Most persons infected with Salmonella develop:
- And abdominal cramps 12 to 72 hours after infection.
- The illness usually lasts 4 to 7 days, and most persons recover without treatment.
How the disease spreads:
- Eating or drinking food or water that is contaminated by rat faeces.
Always wer gloves and a dust mask when entering places where rodents travel such as roof voids and sub-floors and wash hands afterwards.
Always wear gloves and a dust mask when entering places where rodents travel such as roof voids and sub-floors and wash hands afterwards. (See Did You Know section).