Tobacco Hornworm

This caterpillar looks like it has eyes all over its body. What is this unusual crawler, and what it is doing?

—Martha Gordon, Highland, Indiana

Tom: This caterpillar is the common tobacco hornworm. It is a hawk moth in the Sphingidae family, and probably the most common species found on garden tomatoes, as well as many other types of plants. The posture in the photo is a defense position. The crawler will also assume this position if it's disturbed, and often uses this pose as a precaution when it's not feeding. As moths, these creatures are very pretty. They are large in size (with a 4- to 5-inch wingspan), brown in color and have orange squares down each side of their body.