Animals and plants come in many different shapes and sizes. It is only natural that we as humans gravitate toward the larger, more visually appealing ones.

Pandas, tigers, dolphins and elephants are frequent subjects for conservation and also popular attractions when visiting a zoo or aquarium.

Huge redwood trees and vibrant rainforest flowers also draw lots of attention from plant enthusiasts.

Yet there are thousands of animals and plants all around us that receive little, if any, recognition for their role in making the world a better place to live. In fact, many of these important organisms are greeted with fear or disgust by the humans who they are helping on a daily basis. I am, of course, referring to those marvelous animals and plants known as decomposers.

Decomposers are organisms that break down dead or dying organic material such as deceased animals, fallen leaves or those grass clippings from the lawn you just finished mowing. Think of them as mini recycling machines: they break down the nasty stuff and turn it into richly fertile soil that helps new plants to grow. Without decomposers, we would have a bunch of dead stuff just lying everywhere. They are the last, and possibly the most important, step in the food chain.

Decomposers consist mostly of small animals, bacteria and fungi. Specific examples include worms, cockroaches, millipedes, mushrooms and molds. Bacteria are the most numerous of all decomposers and can live in the deepest parts of the ocean, thrive in the vastly cold climates of Antarctica or be found in steamy geysers. Bacteria also are found within our own bodies, helping to digest food and keeping our systems functioning properly. Mushrooms and molds are great for breaking down old trees and plant material. It is probably safe to say that everyone has seen this process occurring on bread or fruit that has been left out for too long.

Then there are my favorites: the creepy crawlies that cause many people to cringe. In our educational programs here at the zoo, we often use Madagascar hissing cockroaches as an example of a decomposer. Found only in the tropical rainforests of Madagascar, these roaches can live two to three years, grow to be about three inches long and love to eat nasty stuff. Vegetables that are moldy and gross, apples that are soggy and disgusting. As long as it is a plant and it is slightly dead, then they will eat it. It truly is amazing what these little invertebrates can do and the significant role they play in the rainforest ecosystem. Perhaps not as surprising is the number of visitors, both adults and children, who pull away and refuse to touch the back of one during a program. And yet they are completely harmless and rely entirely on their camouflage and their ability to produce a loud hissing noise to protect themselves.

Worms are another important decomposer. Their ability to aerate the soil and remove decaying organic matter makes them vital to gardens and compost bins alike. Without decomposers, composting would not even be possible. If you do not have a compost pile already, I encourage you to create one. It is as easy as placing leaves, grass, fruit and vegetable peels, and coffee grounds (no meat products!) into a plastic bin or pile with some dirt and turning it every few weeks to mix and aerate it. Over time, this will create nutritionally rich soil that is perfect for gardening and potting plants.

So the next time you visit the zoo and stop to admire our handsome male lion, Razi, or graceful giraffes, maybe you will think about the other, smaller organisms that are constantly working to keep the world a beautiful place. You can also keep your eyes and ears open for our next Zoo Doo compost sale, where you can purchase some of the zoo's best compost. And as you enjoy that juicy tomato or those crunchy green beans from your fertilized garden next year, make sure to say a mental "thank you" to the decomposers that made it all possible.

Visit our award-winning web site at