This is the iconic caterpillar that is said to predict the severity of the upcoming winter. Woolly Bears are common throughout North America at lower elevations and feed on a wide variety of plants, including grasses, asters, birches, clover, corn, elms, maples, milkweed and sunflowers. In fall, the full-grown caterpillars wander and are often seen crossing roads. They are on the hunt for sheltered places in which to overwinter — hollow logs, piles of leaves, cracks in foundations, stacks of firewood. The caterpillars have a remarkable capability to withstand freezing temperatures thanks to a special “antifreeze ” (glycerol) in their body. In spring, they will pupate within cocoons made from their hairs and emerge as the lesser-known adults.
Size: Larvae to 57 mm
Photo by: Rose Marchak on 10/22/21 near Missoula, MT
