It's that time of year in much of the United States! Butterflies are beginning to wake from their winter slumber.
Viceroy caterpillars spend the winter in a leaf that they rolled into tight tubes. When days are longer and warmer, the caterpillar emerges from its tube (hibernaculum) and begins eating new fresh leaves on the willow tree or shrub.
When visiting a willow in the late fall, winter, or early spring, watch for these little tubes. Inside, a caterpillar may be as eagerly awaiting spring as we are.