*Butterflies are usually active by day and have threadlike, knob-tipped antennae, a small body, and broad wings. Moths generally are active at night, have antennae in many shapes (but never with knobs), a stout body, and narrow wings.
*The monarch butterfly is the official State Insect of Illinois.
*The largest moth in Illinois, the cecropia, is also the largest moth in North America. It has a wingspread of five to six inches.
*Female moths release chemicals into the air to attract males. In some species, the male can find the female from one to three miles away.
*Several species of Lycaenidae butterflies have caterpillars that are "tended" by ants. The ants protect the larvae from predators in exchange for food in the form of sweet excretions they take from the larvae.
*Clearwing moths of the family Sesiidae fly about in the daytime, unlike most other moths. They are mimics of wasps, which serves to protect them from predators.
*The spicebush swallowtail starts life as a caterpillar that mimics a bird dropping. As it grows bigger, the caterpillar then mimics a rough green snake. As a chrysalis, it mimics a dead leaf. As an adult, it mimics another swallowtail, the pipevine, that is distasteful to predators.
*The dog face sulphur butterfly (Colias cesonia) has an image that resembles a French poodle on each wing.
*Moths first appeared during the age of the dinosaurs, about 200 million years ago. Butterflies developed about 40 million years ago.
*In the fall, monarch butterflies migrate approximately 80 miles per day to overwinter in the mountains of central Mexico. When they begin their flight back in the spring, they lay eggs along the way.
*Some pyralid moths are aquatic: their eggs are deposited under water, and their larvae develop external gills. One species, Petrophila bifascialis, lives in a silken web in fast flowing streams where it feeds on diatoms and algae that it scrapes from rocks.
*The red-humped caterpillar (Schizura concinna) defends itself by spraying an acid up to eight inches from an opening underneath the prothorax.
*Some moths (including some inchworms and snout moths) have "ears" on the first abdominal segment that they use to detect the high-pitched calls of bats and thus aid their escape from these predators. Other moths have hearing organs on the thorax (including some owlet moths, tiger moths, lichen moths, and wasp moths).