Invertebrates are animals without backbones. In estimates of the number of species found on earth (somewhere between 5 and 30 million) invertebrates compose around 99 percent of all species known and unknown. Invertebrates are grouped based on similarities. Some of the more interesting and colorful groups include the butterflies, moths, dragonflies, and damselflies. You will find some nice pictures of some of the more noticeable invertebrates found on BNL on the accompanying pages.