The ice crystals will eventually expand and rupture the body cells, killing the insect. Most insects use a form of antifreeze to survive freezing temperatures, van Randen says. As the temperature drops, their cells produce glycerol, which prevents water crystals from forming within the cells. This two-step process, called supercooling, allows body fluids to remain liquid at temperatures far below their normal freezing point. Supercooling is highly effective.
Some insects have another strategy.
They can isolate ice crystals between cells and allow them to form without danger of cell damage. The ability of insects to survive even the extreme conditions of a Yukon winter astonishes van Randen. Most insects spend the winter in larval form. Larvae seem to be better at producing glycerol, van Randen says, and therefore can survive through colder temperatures than adults. In cases where both larvae and adults survive, they often use different strategies, he says.