Woolly Bear Caterpillars Can't Predict Winter

The woolly bear caterpillar is a common sight in Michigan during fall, but don't rely on it to predict the severity of winter. According to folklore, the width of the caterpillar's black and brown-to-red bands can indicate how harsh the upcoming winter will be.

Michigan State University's Extension notes that 'wide black stripes mean a bad winter, whereas a wide brown stripe in the middle means a mild winter.' However, the National Weather Service cautions that this is not based on scientific fact. Instead, the caterpillar's coloring is determined by factors such as hatching conditions, genetics, and behavior.

The woolly bear caterpillar is actually harmless, and does not sting or bite. It eats leaves, grasses, and flowers, including asters, clovers, and sunflowers. The caterpillars can travel up to 4 feet per minute, and produce sounds to find mates or deter predators.