Colour varies considerably, from soft grey to reddish-brown, often with an area of brick red on the upper back, and always with a conspicuous black stripe running from the tip of the muzzle through the eye to the base of the small, round-tipped ear.

[15] However, like other mammals that eat termites or ants, the numbat has a degenerate jaw with up to 50 very small, nonfunctional teeth, and although it is able to chew,[15] rarely does so, because of the soft nature of its diet.

As a result, although not all individuals have the same dental formula, in general, it follows the unique pattern: 4.1.3.1.43.1.4.1.4[15] Like many ant- or termite-eating animals, the numbat has a long and narrow tongue coated with sticky saliva produced by large submandibular glands.

A further adaptation to the diet is the presence of numerous ridges along the soft palate, which apparently help to scrape termites off the tongue so they can be swallowed.

However, their range has significantly decreased since the arrival of Europeans, and the species has survived only in two small patches of land in the Dryandra Woodland and the Tone-Perup Nature Reserve, both in Western Australia.

Today, numbats are naturally found only in areas of eucalypt forest, but they were once more widespread in other types of semiarid woodland, spinifex grassland, and in terrain dominated by sand dune.

[22] After measures aimed at excluding feral cats, the number of numbats trapped during annual population surveys in the Dryandra Woodland had increased to 35 by November 2020, after recording just 10 in 2019 and 5 in 2018.

[24] Reintroduction began at large fenced reserves in Mallee Cliffs National Park in NSW in December 2020,[25] and on South Australia's Eyre Peninsula in 2022.

[26] Attempted reintroductions of the species to fenced reserves in two other areas – one in the South Australian arid zone, near Roxby Downs, and the other in the northernmost part of its former range, at Newhaven Sanctuary in the Northern Territory – both failed.

[30] Numbats are insectivores and subsist on a diet of termites (of the genera Heterotermes, Coptotermes, Amitermes, Microcerotermes, Termes, Paracapritermes, Nasutitermes, Tumulitermes, and Occasitermes).

It uses a well-developed sense of smell to locate the shallow and unfortified underground galleries that termites construct between the nest and their feeding sites; these are usually only a short distance below the surface of the soil, and vulnerable to the numbat's digging claws.

Unusual for marsupials, female numbats have no pouch, although the four teats are protected by a patch of crimped, golden hair and by the swelling of the surrounding abdomen and thighs during lactation.

[15] At the time of European colonisation, the numbat was found across western, central, and southern regions of Australia, extending as far east as New South Wales and Victorian state borders and as far north as the southwest corner of the Northern Territory.

[15] The first record of the species described it as beautiful,[37] and its popular appeal led to its selection as the faunal emblem of the state of Western Australia and initiated efforts to conserve it from extinction.

When the Western Australia government instituted an experimental program of fox baiting at Dryandra (one of the two remaining sites), numbat sightings increased by a factor of 40.

An intensive research and conservation program since 1980 has succeeded in increasing the numbat population substantially, and reintroductions to fox-free areas have begun.

George Fletcher Moore, who was a member of the expedition, drew a picture in his diary on 22 September 1831, and recounted the discovery: Saw a beautiful animal; but, as it escaped into the hollow of a tree, could not ascertain whether it was a species of squirrel, weasel, or wild cat...and the following day: chased another little animal, such as had escaped from us yesterday, into a hollow tree, where we captured it; from the length of its tongue, and other circumstances, we conjecture that it is an ant-eater—its colour yellowish, barred with black and white streaks across the hinder part of the back; its length about twelve inches.