Many of us are fascinated by diversity among life forms. My lifelong interest in the natural world began as a boyhood obsession with identifying birds; I started my “Life List” at age 12. Today birding is the world’s largest nonconsumptive outdoor activity. Butterfly watching runs a close second.

Moth watching, or “mothing,” has come into its own. There are more than 110,000 moth species in the world, more than 11,000 in North America, and more than 2,300 in New England. Most are nocturnal. Many are as colorful as butterflies with equally interesting patterning on their wings and bodies. With a little effort, “moth-ers” can experience the diversity and beauty of moths as revealed on porch walls and the trunks of backyard trees.

The old saying “like moths to a flame” reflects an ancient observation about moths: They are attracted to light. Scientists still are not certain why. The oldest theory is based on the observation that moths use the light of stars and the moon to orient themselves during nocturnal flight. They become disoriented by our artificial lights and, in effect, find themselves landing on the moon. Actually, it is more like landing on the sun in terms of light intensity, and the moths react as if it is daytime – they come to rest.

Regardless of the “why,” leaving the porch light burning through a summer night is bound to attract many moth species. One mid-July morning I counted at least 20 different species resting on the porch walls, railings and posts. Many stayed the entire day, allowing me to photograph them for later identification using field guides.

When attracting moths with light it is important not to keep the light on every night. The moths, many of which live for only a few days, should be allowed the opportunity to carry on with normal activities undisturbed.

Attracting night-feeding moths for close observation is done by baiting, an exciting activity for those willing to tromp around the yard in the dark. Essential ingredients for moth bait are stale beer and brown sugar; optional ingredients include fruit juice, rotten fruit (bananas are excellent) and molasses. There are no absolutes; part of the fun is trying different combinations to see which work best.

The consistency of the bait should be thick enough to spread on the trunks of trees without running. Bait that reaches the ground will quickly attract ants and slugs.

Fermented bait makes a better moth attractant, so allow it to sit for several days before use. Keep the container lid slightly open to allow gases to escape.

Spread the bait over a square foot of trunk surface with an old paintbrush. I apply it at eye level so that I can photograph more readily the moths that come to feed. I brush on the bait just before dusk and return to check for feeding moths between 10 p.m. and midnight.

Approach the baited trees slowly, using a flashlight. Avoid shining the light directly on the baited area as many moths so disturbed will fly off immediately. I find it helpful to invite a partner along to hold the light while I photograph the moths.

Anyone interested in discovering moths also should discover John Himmelman. His book, “Discovering Moths” (2002, Down East Books), is an excellent introduction to mothing. He also maintains a Web site, www.connecticutmoths.com, with numerous photos to aid in identification.