A grisly trick helps snow flies survive freezing: self-amputation

The insects cast off freezing limbs, preventing ice from spreading through their bodies

A photo of a snow fly standing on ice.

In the wild, snow flies are often missing legs, like the insect shown here. The flightless flies my self-amputate limbs as a way to survive the cold.

Trasroid/Flickr (CC BY-NC 2.0)

A few years ago, John Tuthill was trail running in the Cascade mountains in Washington state when he spotted something dark skittering across the snow.