[2][4] It is known for its slow rate of development, as its full caterpillar life cycle may extend up to 7 years, with moulting occurring each spring.

[4][6] Rare among Lepidoptera, it undergoes an annual period of diapause that lasts for much of the calendar year, as G. groenlandica is subject to some of the longest, most extreme winters on Earth.

[7] The Arctic woolly bear moth also exhibits basking behavior, which aids in temperature regulation and digestion and affects both metabolism and oxygen consumption.

[9] This moth was likely first discovered on 16 June 1832 on the beach of Fury Bay, Somerset Island, northern Nunavut, Canada, by the crew of the Arctic expedition searching for the Northwest Passage (led by John Ross).

John Curtis, who studied the entomological specimens obtained from the voyage, described Gynaephora rossii from the invertebrates brought-back; however, in 1897 Harrison G. Dyar showed that, when compared to the caterpillars of G. rossii he had previously collected from the heights of Mount Washington, New Hampshire, in fact caterpillars of G. groenlandica had been collected in 1832, and Curtis had based his description of the larvae on the wrong species.

[10][11] Before that, however, specimens were recovered in 1870 from northern Greenland by Gottlieb August Wilhelm Herrich-Schäffer, on board the Germania on the Second German North Polar Expedition (led by captain Karl Koldewey).

[1] G. groenlandica was first believed to be endemic to the High Arctic,[12] until a 2013 article reported the discovery of two populations neighbouring each other in alpine environments within southwest Yukon, 900 km south of their previously known distribution.

[2] In general, G. groenlandica larvae are larger (~300 mg), and are densely coated in soft-looking hairs, which may actually be used as a defense mechanism to irritate the skin and soft tissues of would-be predators.

[7] At two distinct field sites on Ellesmere Island, it was discovered that G. groenlandica, when in a diapausal state, tend to exist in specific microhabitats rather than in a random geographic distribution.

This implies that the acquisition of high quality resources is a primary reason for the movement of G. groenlandica larvae between host plants.

[4] The lower latitude Canadian populations of G. g. beringiana of the alpine environments of southwest Yukon have larvae eating a broader spectrum of plants and proportionately less S.

[9][18] While larvae rarely eat the catkins (petal-less flower clusters) of S. arctica, they readily consume the plant's leaves.

[17] Larvae appear to only feed in June, which is when the leaves of S. arctica reach their peak concentrations of nutrients and carbohydrates such as starches and sugars.

[9] Arctic woolly bear moths remain larvae for the vast majority of their lives, with the exception of up to 3–4 weeks of a single summer.

[9] While they remain in their extended larval stage, G. groenlandica experience annual winter diapauses that commence in late June or early July.

The High Arctic presents a short growing season of 45–70 days, and the G. groenlandica cease foraging at the end of June, prior to mid-summer.

[19] In late June or early July, the larvae prepare to overwinter by weaving silken hibernacula and entering diapause until the subsequent snowmelt.

[9] The presence of the caterpillars eating plants in a particular area appears to have a positive correlation with herbivory of the collared pika (Ochotona collaris) in southwest Yukon.

[7] The Arctic moth Psychophora sabini has some of its defensive reactions to bats, presumably due to the population being isolated from this predator.

When Arctic woolly bear moths are exposed to bat-like ultrasound (26 kHz and 110 dB sound pressure level root mean square at 1 m), males respond by reversing their flight course.

Secondly, an auditory system would compete for space with the ovaries, and the cost of this defence mechanism may outweigh the benefit of having fully functional reproductive organs.

[12] Many G. groenlandica caterpillars perish during development due to parasitoids, namely the tachinid fly (Exorista thula) and the ichneumonid wasp (Hyposoter diechmanni).

Despite co-occurring there with the closely related Gynaephora rossii, E. thula is only known to attack G. groenlandica, whereas Chetogena gelida is host specific to G.

Larvae tend to follow the direct angle of the sun's rays in order to maintain maximal absorption of sunlight.

[4][7][6] This peak temperature is generally only reached when larvae lie in midday sun, surrounded by snow, on a day with minimal wind.

[4] It has been suggested that without the help of basking in 24-hour sunlight during High Arctic summers, larvae would rarely exceed their developmental threshold of around 5 °C (41 °F).

[7] Encasing itself within a hibernaculum during diapause serves several functions: protection from parasitoids, avoidance of diminished nutrient concentration in their primary food source, Salix arctica, degradation of mitochondria linked to decreased metabolism (hypometabolism) and antifreeze production, and general conservation of energy reserves.

[21] As temperatures decrease in the late Arctic summer, larvae begin synthesizing cryoprotective compounds, such as glycerol and betaine.

Accumulation of these "antifreezes" (which protect cells from cold conditions) is aided by the bottlenecking of oxidative phosphorylation through mitochondrial degradation.

While the larvae continue to produce energy from stored glycogen in their frozen state, this mitochondrial degradation causes their metabolism to drop so low as to almost stop entirely, inducing dormancy.