Most people do not think too kindly of caterpillars — especially those with flower or vegetable gardens — and certainly farmers, who do all that they can to rid their crops of the little eating machines.
When one considers the diversity of butterflies and moths, it is quite overwhelming. There are researchers who spend their entire lives searching out new species, and others who spend their lives trying to come up with new chemical technologies to wipe out insects, including caterpillars, that are harmful to crops.
One thing is for certain, caterpillars play an amazingly important role in controlling the growth of their host plants and in turn they are food for a tremendous number of insects, spiders, amphibians, reptiles, birds and mammals. Some species are caterpillar dependent, including many of the neotropical migrant birds that time their arrival in North America with the emergence of caterpillars upon which they feed. We must also not forget that every gorgeous butterfly in the sky began its life as an egg that hatched into a caterpillar, and after a number of molts metamorphosed into the butterfly.
There is also one other majorly important role in which caterpillars provide and that is “FRASS.” Frass is a wonderful word and one that many people with extremely large vocabularies would have difficulty defining. Frass is caterpillar poop! Yes, caterpillar poop has its own special name and rightly so. It is vitally important to most ecosystems especially in tropical areas and many of the temperate regions as well. Basically, frass comes in many sizes, dependent upon the size of the caterpillar. Caterpillars are basically eating machines and they eat, poop, eat, poop, eat and poop. When you realize just how many caterpillars there are, just imagine how much frass is produced.
I have been under trees with good infestations of caterpillars where it almost appears to be raining, but the pitter patter on the leaf litter is not rain it is caterpillar frass. Frass actually is very important as it provides nutrients that will be readily available to the forests on the very next rain. I have often stopped and collected a handful of frass and asked children or adults that are with me: “Do you know what this is”? I have them pick up a piece and look at it closely. Often, larger frass looks similar to miniature ears of corn. The shape has to do with the intestine being able to absorb as many nutrients as they can from a very low nutrient food base. So, there is a large surface area on the frass which looks like corn on the cob. After looking at frass for a few minutes, I then tell the people what they are holding: Caterpillar Poop! They drop it immediately, but most people come away with a greater appreciation for caterpillars and their role as providing massive nutrient loads in the forest. They also learn that it is best not to hold things that Greg or other naturalists may place in their hands. By the way, checking out elephant dung is just as rewarding!
Naturalist Greg Greer  is a favorite among IE travelers, and has gained a reputation for his friendliness and good humor, along with his incomparable knowledge of natural history, photos and articles have been widely published in books and magazines, including Georgia Outdoor News, Bird Watcher’s Digest, Alabama Outdoor News, Riversedge and Southern Wildlife.