Woolly caterpillars are better known as woolly bear caterpillars. There are more than eight types of woolly bear caterpillars, all of whom have bristly, dense hair that covers their entire bodies. Woolly caterpillars eat grass and plants and will turn into tiger moths.
The banded woolly bear caterpillar, or Pyrrharctia isabella, is the most well-known of woolly caterpillars. The name refers to the caterpillar's band of colors -- black on the ends and reddish brown in the middle. Woolly bear caterpillars are found in southern Canada, Mexico and the U.S., but nowhere else. They turn into Isabella moths as adults.
Hickory tussock moth caterpillars, or Lophocampa caryae, are white and black. Recognized by the black tufts on the different segments of their bodies, they feed on hickory, butternut and walnut trees. The caterpillars spin cocoons in the fall and tiger moths emerge in the spring.
The giant leopard moth caterpillar, Expanthjerica scribonia, is covered with black hairs that are all the same length. When the caterpillar curls up into a ball, it is possible to see its red segment rings. Typically, these caterpillars are seen in the fall as they look for shelter from the winter. In the spring, the caterpillars emerge as giant leopard moths.
The pale tussock caterpillar, Halysidota tesselaris, is large and brightly-colored. They can be yellow-brown, tan and gray with white and black lashes on the second or third body segments. The moths that emerge in the spring are much paler than the caterpillars, which can be found in the eastern areas of Mexico, the U.S. and Canada.