Most insects hide in winter. Winter stoneflies are one of the few insects that are active. Special compounds in their blood act as anti-freeze and keep them from freezing.
The adults emerge from the water in midwinter and mate. The female returns to the water to lay her eggs. After the eggs hatch, the nymphs live underwater and molt anywhere from a few times to more than twenty. When they are mature, they crawl out of the water, molt one last time, emerging as the winged insect you see here, and begin the cycle again. Look for them on warm day in January or February near water sources.
Looking for these insects was on the January Nature Calendar, but we didn’t find them until the first week in February. Maybe they were around before then, but we didn’t see them. According to Bug Guide, the ones we found seem to be small winter stoneflies (family Capniidae).
More information on winter stoneflies: Winter Stoneflies Sure are Super Cool.
More winter nature activities: