Fact-checked against 1 source · Updated 20 September 2026On this page
Which rats live in the UK?
There are two species of rat in Britain. The common one is the brown rat (Rattus norvegicus), also called the common rat. The other is the black rat (Rattus rattus), also called the ship rat, which is now rarely found in the UK and is occasionally seen in shipping ports. If you have rats in Newark-on-Trent, they are almost certainly brown rats.
| Detail | Brown rat | Black rat |
|---|---|---|
| Typical weight | About 0.5kg | About 0.25kg |
| Length (without tail) | About 23cm (range 15–28cm) | About 15cm |
| Muzzle | Blunt | Pointed |
| Ears | Small, hair-covered | Large, almost hairless |
| Eyes | Small | Large |
| Tail | Shorter than the body | Thin, longer than the body |
| Where found | Everywhere: homes, gardens, sewers, farms | Rare; occasionally ports |
Source: BPCA. Brown rats can occasionally get closer to 1kg where food and shelter are plentiful, but that is rare.
How fast do rats breed?
Rats breed faster than most people expect. In good conditions a female can have a litter about every six weeks, each of six to eight pups. Pregnancy lasts around 21 days, and pups are weaned after another 21. A female can become pregnant again within 10 to 24 hours of giving birth, and young rats can be sexually mature after only five weeks. The BPCA notes that, in theory, a single pair of brown rats could produce as many as 200 young, and around 2,000 descendants, in a year.
That is why a “couple of rats” in the garden can become a colony by winter, and why noises in the loft should be checked early.
How long do rats live?
Wild rats live for about a year on average, because of predators and other hazards. Pet rats, protected from those risks and well fed, often live two to three years. A year is still plenty of time to breed several times.
What can rats do?
- Squeeze through small gaps. The BPCA says rats need a gap of only about 15mm to get into a structure — roughly the width of two fingers. See rat proofing.
- Climb and jump. Rats can climb brick walls and pipes, jump about three feet (roughly a metre) straight up and four feet horizontally, and survive a fall of up to 50 feet.
- Feel and hear their way around. Rats have poor eyesight but a well-developed sense of smell, taste and touch. Their whiskers are believed to be as sensitive as a human’s fingertips, and they can hear ultrasound up to around 90,000Hz.
- Gnaw through almost anything. Rats gnaw to keep their teeth in shape, including wood, plastic, lead pipes, and the sheathing on electrical cables, which is a fire risk.
What do rats eat?
Rats are nocturnal and feed mostly at night, eating around 50g of food a day on average. They prefer cereal products but aren’t fussy: they will eat almost anything, including other small animals. That is why bird seed, compost, pet food, chicken feed and household waste all attract them. See our prevention checklist.
Signs that rats are around
- Droppings: dark, pellet-shaped and about the size of large grains of rice, clustered in the same places. The BPCA says a rat can leave up to 40 in a night.
- Gnaw marks on cables, woodwork, plastic and pipes, and torn bags of food.
- Smear marks: greasy residue where rats’ coats rub against walls along regular routes.
- Footprints and tail marks in dust in unused areas.
- Sounds: scratching, gnawing and scuttling, and sometimes teeth-grinding and chattering when stressed.
- Burrows: holes beside solid structures such as walls and sheds are a sure sign of a nest.
Rats are social: one usually means more
Rats are social animals, so if you see one there are likely more nearby. A single sighting is rarely a lone animal, which is why prompt professional advice is better than waiting.
Rat facts: common questions
How big is a brown rat?
An adult brown rat is typically around 23cm long without its tail (the BPCA gives a range of 15–28cm) and weighs about half a kilo.
How many rats are there in the UK?
Nobody knows exactly. The BPCA says estimates range from 10.5 million to 120 million, and that milder winters in recent years are thought to have helped rat populations to thrive.
Can rats really squeeze through such small gaps?
Yes. The BPCA says a gap of about 15mm is enough, so sealing small holes around pipes and vents matters.
Are black rats a problem in Newark?
Very unlikely. Black rats are now rare in the UK and mostly found around ports. Brown rats are the ones to expect.
Sources and further reading
Facts on this page were checked against the sources above on 20 September 2026. Laws, prices and council services change, so check the current position before relying on them.
This site connects households and businesses in the Newark-on-Trent area with an independent local rat-control technician. We are not the servicing contractor and do not carry out treatment ourselves. See our terms & disclosure.