Woolly Worms and Weather Just yesterday, a woolly bear caterpillar, or woolly worm, was crossing the road in front of me. I pulled over and picked it up, noting the extent of black on each end of its otherwise brown body. Its head was only slightly black and its tail end had no black at all. According to folklore, this predicts a very mild winter. The Woolly Bear caterpillar is the larval stage of a tiger moth. The moth itself is about 2 inches long and yellowish in color. On its body are three rows of six black dots. The caterpillar is also about 2 inches long and is densely covered with stiff hairs, which make it look as woolly as a bear. The hairs are black on the head and tail, but brown in the middle. When the caterpillar is picked up, it curls into a tight ball with the bristly hairs sticking out in all directions. These prickly hairs discourage its predators, mainly rodents like mice, from eating it.  There are several other tiger moths in the area, and their caterpillars are similar to woolly bears. They are about the same size and covered in stiff hairs. They even curl up into a ball like woolly bears do. The yellow woolly bear is pale yellow and is very common. The great leopard moth and the hickory tiger moth caterpillars are solid black.  Woolly bears are very active this time of year as they search for a place to spend the winter. You’ll find them crossing roads, crawling across your lawn, or cruising on paths through the forest. They seem to race across the paths and are, in fact, pretty fast for a caterpillar. They’ve been clocked at four feet per minute, which translates into about 0.05 miles per hour. They spend the winter hidden underneath bark or rocks, and emerge in the spring to feed for a few days before they spin a cocoon and turn into moths.  The caterpillars eat a variety of plants that are found in old fields and forest edges, including grass, clover, plantain, and dandelion. These types of plants occur along roadsides and paths, which is why the caterpillars are often seen there. Underneath the stiff hairs, the woolly bear’s body is divided into 13 segments. According to legend, a long brown middle predicts a mild upcoming winter, whereas long black ends and a short brown middle predict a harsh winter. There are several methods for determining the length of the brown section, but The Old Farmer’s Almanac reports that most soothsayers count the number of brown segments. In Banner Elk, NC, home of the Woolly Worm Festival, woolly worms are raced up a string, and the winning worm is used for the prediction. There is a special formula used to “read” the winning worm.  The 13 segments correspond to the 13 weeks of winter, and the severity of cold during each week is predicted by the color of that segment. This year’s festival is this upcoming weekend, October 20 and 21, in Banner Elk. Their website is http://banner-elk.com and the phone for the chamber of commerce is 1-800-972-2183. There is some scientific evidence that the amount of black is determined by the age of the caterpillar as well as by the temperature and amount of moisture in its habitat during its early life. The woolly bears that are active at this time of year were hatched from eggs over the summer. So while the woolly bears might predict the weather, it’s probably the weather of the past summer rather than the upcoming winter. Maybe that Woolly Bear I found was reporting that August, when it probably hatched, was warm and dry. Was it? Copyright 2001 by Jennifer E. Frick