These wingless insects are so sensitive to heat they die in your living room

Nature · Published 3 October 2026 · Updated 25 October 2026 Swipe more like this →

In short: Grylloblattidae, or ice crawlers, are extreme cold-weather specialists that thrive on glaciers and mountain peaks. These nocturnal insects are so physiologically tuned to freezing temperatures that even a mild rise in heat can be fatal. As global temperatures climb, these unique survivors face an increasingly precarious future in their isolated habitats.

First identified in 1914 by E.M. Walker and T.B. Kurata, Grylloblattidae—commonly called icebugs—are a family of wingless, nocturnal insects that inhabit some of the coldest environments on Earth. They are true extremophiles, typically found in leaf litter, under stones, or near the edges of glaciers and ice sheets. Their biology is so specialized for the cold that most species perish at temperatures as low as 10 °C, and they are often killed when the ambient heat rises just 5 °C above their optimal range.

The family comprises about 34 extant species across 5 genera, with a patchy distribution spanning western North America, East Asia, and parts of Siberia. Because many species are restricted to single sites or small, isolated populations, they are highly vulnerable to environmental change. Their survival strategy involves seasonal movement to maintain an optimal temperature, often retreating beneath snow packs to avoid freezing when temperatures drop too low or seeking cooler micro-climates as the seasons shift. They are omnivorous, feeding primarily on carrion and dead arthropods, though they will consume plant material when carcasses are scarce.

Evolutionarily, the group is thought to have emerged from the Grylloblattida, a lineage of winged insects that appeared over 300 million years ago during the Late Carboniferous. While modern ice crawlers are wingless, they share distinct anatomical similarities with ancient relatives, such as the winged Aristovia found in mid-Cretaceous Burmese amber from approximately 100 million years ago. Today, these insects are considered endangered, as their narrow physiological tolerances and limited ranges make them particularly susceptible to the effects of a warming climate.

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