Woolly rats are found in Indonesia and Papua New Guinea, usually in mountain forests or mountain grasslands. Some woolly rat species are called giant rats, since they can weigh almost a kilo and a half. That's about three to six times what a typical pet rat weighs.
Scientific name: Mallomys
Black and white images from a camera trap reveal a new species.
One way to find interesting animals in the unexplored forests is to set up camera traps, in the hope you find something interesting. Cameraman Gordon Buchanan and mammal expert Kris Helgen come across some pictures of what might just be a new species of giant woolley rat living in the crater of Mount Bosavi.
One of the world's largest rats would give a house cat a run for its money.
In Land of the Lost Volcano, Gordon Buchanan is called to the discovery of a very special animal. It's a completely new species of rat... but it's the size of a cat. Unafraid of humans, thanks to the remoteness of its mountain home, the giant rat happily grooms itself while the team sits around discussing it, completely awestruck.
The shading illustrates the diversity of this group - the darker the colour the greater the number of species. Data provided by WWF's Wildfinder.
The Woolly rats can be found in a number of locations including: Asia. Find out more about these places and what else lives there.
Mallomys is a genus of rodent in the family Muridae. The name of the genus is formed from the Greek μαλλός, mallos, wool, and μῦς, mus, mouse/rat. These very large rats weigh between 0.95 and 2 kilograms (2.1 and 4.4 lb) and are native to highlands in New Guinea. Little is known about their behavior, but they are believed to feed on leaves, grasses and other plant material.
It contains the following species:
Conservation International (CI) and the Indonesia Institute of Science (LIPI) discovered two possibly undescribed mammals upon visit of the Foja Mountains in June 2007: a Cercartetus pygmy possum, one of the world's smallest marsupials, and a 1.4 kilograms (3.1 lb) Mallomys giant rat (five times the size of a Brown Rat) - found in Indonesia's Papua in 2005.
Take a trip through the natural world with our themed collections of video clips from the natural history archive.
Watch the year's highlights from the BBC's exploration of the planet's hidden corners and rarest creatures: from the turquoise seas of the South Pacific to the Lost Land of the Volcano.