Animal · United Kingdom, Germany, France
Brown rat
Rattus norvegicus — the name this animal has in the language scientists everywhere share.
The brown rat is one of the most successful mammals on Earth and lives on every continent except Antarctica, almost always close to people. It swims well, gnaws through wood and squeezes through any gap its head fits into.
Picture credit: Chuck Homler d/b/a Focus On Wildlife (CC BY-SA 4.0) · Zeynel Cebeci (CC BY-SA 4.0) · Wikimedia Commons
Where does the brown rat live?
Home: Sewers, cellars, farms and river banks worldwide.
In the wild it lives in these countries: the United Kingdom, Germany, France, the Netherlands, the United States, China, Russia, Australia.
Conservation status from the IUCN: not in danger.
The short profile
Fully grown: 15-28 cm long, plus a 10-24 cm tail. It weighs about 0.3 kilograms. On the menu: both plants and meat.
The story behind it
The brown rat came originally from the grasslands of northern China and travelled the world in the holds of ships. Wherever it landed it dug burrows with several entrances, learned which food was safe and which was not, and multiplied fast: a female can have up to five litters a year, with about seven young in each. Rats can be wary of anything new, tasting a small amount of unfamiliar food first and waiting to see what happens, which is one reason poison often stops working on them. In the wild most rats do not reach their first birthday. The tame rats in laboratories and living rooms are the same species, bred over two centuries into calm, curious animals.
Find it on the globe
Brown rat is there as a tiny animated figure that breathes and looks around. From far away the planet is only a blue ball; detail arrives as you zoom in, and this one appears once you are close enough. Open it on the globe.
It sits at its real coordinates, not near them — the same numbers listed in the facts above. Switch off the layer for this kind of place and it disappears again; the buttons for that are down the right-hand edge.
Questions children ask
Where do brown rats come from?
From the grasslands of northern China and the areas around them. Ships carried the species along trade routes from the eighteenth century onwards, and today it lives on every continent except Antarctica.
Are pet rats the same animal?
Yes. Pet rats and laboratory rats are brown rats that people have bred for about two hundred years, choosing the calmest animals each time. They are the same species as the rat in the sewer, only far tamer.
Can rats swim?
Very well, both at the surface and under it. Brown rats often live along canals and river banks and use the water as a road, which is also why they get along so well in sewers.
Where these numbers come from
Every figure on this page was checked against public reference sources before publication. Where sources genuinely disagree, the text says so.
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