There’s a rodent in my house? Is it a rat or a mouse?
When you notice that an uninvited guest is nibbling your food while you sleep at night, you will no doubt suspect rodents of paying you an unwelcome visit. But what type of rodent do you have? How can you tell?
When you know the difference between a rat and a mouse, you can customise your solution to your specific rodent problem.
You can usually tell the difference between rats and mice simply from their appearance.
Size is usually a good indicator of the type of rodent you are dealing with. Mice are generally smaller than rats, although mice can be a similar size to baby rats.
- Between 3 and 10 cm in length
- Long, thin tail covered in hairs
- Large ears
- Covered in short hairs with lighter coloured bellies
- Weighs between 12 and 45 grams.
Rats are generally a lot bigger than mice. You can also spot other distinctive rat characteristics.
- Between 16 and 40 cm in length depending on the species.
- Thick, hairless tail
- Large feet
- Weigh between 150 and 300 g, also depending on the species.
However, there are some differences between brown and black rats.
Black rat characteristics
- Between 16 and 24 cm long
- Tail is longer than head and body
- Weighs between 150 and 200 g
- Have a pointed nose, large ears and a slender body
Brown rat characteristics
- Can grow up to 40 cm in length
- Tail shorter than head and body
- Blunt nose and small ears
- Thicker body compared to black rat.
Rodents start to look for a new habitat when the weather starts to get colder. Our homes become an attractive destination, because they provide warmth, shelter and food.
Mice prefer to live on the ground and nest in burrows. However, they are capable of climbing great heights, and may build nests in cavity walls, behind fridges and under floorboards.
A rat’s nesting environment depends on whether it’s a brown or black rat.
Where do black rats live?
Black rats prefer to nest high under roofs. Because they are such agile climbers, they may even choose to nest in trees if the weather is warm enough.
Where do brown rats live?
Unlike black rats, brown rats usually nest in burrows or on the ground. They may dig burrows near sewer systems, compost heaps, sheds or garages.
The breeding habits of rats and mice can exacerbate your rodent problem. They breed large litters quickly. Newborn rats and mice are blind, hairless and completely dependent on their mothers.
- Give birth to litters of around 4-16 pups.
- A fully mature female mouse can give birth to 7-8 litters a year
- It takes 8-12 weeks for mice to reach maturity
- Black rats give birth to litters of 5-10 pups whilst brown rats give birth to 7-8 pups per litter
- Both species of rat can have anywhere between 3-6 litters per year
- It takes brown rats between 10-12 weeks to reach maturity whilst only 7-8 weeks for black rats.
You can also identify your type of rodent problem by examining the droppings. In general, mice produce a lot more droppings than rats. However, if you have a large rat infestation, you’re going to see a lot of droppings!
Mouse droppings are approximately 1-3mm in length and they are often found scattered randomly during an infestation. A mouse will normally deposit around 80 droppings per day which are usually granular in shape, black in colour, and found near their nesting sites.
Rat droppings are approximately 3-8mm in length and are usually a banana shape (depending on the species) and a dark brown colour. Rats usually produce around 40 droppings per day which are a dark brown colour.
Brown rat droppings
Brown rat droppings are wide and typically found in a tapered, spindle shape resembling a large grain of rice.
Black rat droppings
Compared to brown rat droppings, black rat droppings are long and thin and smaller. They are more regular in form and resemble the shape of a banana with pointed ends.
Neither mice nor rats are fussy eaters. They simply like to eat a lot of food! And they will consume either meat or vegetables. However, each rodent has its own food preferences.
Mice prefer carbohydrates such as cereals. A good mouse prevention technique is to store cereal in plastic, air-tight, containers. When they are eating grains mice will nibble at it to remove the outer husk and eat the white endosperm inside. Mice also have a preferred spot for foraging and will seek food in the same places. Mice will eat around 3g of food a day and only need 3 ml of water a day to survive.
A rat’s diet and eating habits depend on the species. They will eat around 15-30 g of food per day and will drink between 15 and 60 ml of water a day.
What do brown rats eat?
Like mice, rats prefer to eat cereals. When eating, mice will cut the grains giving the appearance it has been chopped. They also share the same eating habits as mice in that they will seek food from the same places. They can drink up to 60 ml of water a day.
What do black rats eat?
Black rats are different in that they prefer to eat fruits. They tend not to eat from the same location on consecutive nights, and they will drink around 30 ml of water a day. Because of this baiting can be quite difficult as it requires small, multiple, baiting points containing moist food.