Since 1998 when the doors opened, he's been collections manager for the Sophia M. Sachs Butterfly House in Chesterfield.

His tiny charges crave the warmth and high humidity of the conservatory area where they fly freely around visitors.

"Typically, we have 1,500 to 2,000 butterflies in here but, for our March Morpho Mania event (featuring bright blue morpho butterflies from Costa Rica), we have about 4,000," said Deering, 40.

He and Jessica, his wife of 15 years, work together. She's guest services manager for the Butterfly House. The couple has a 4-year-old daughter, Lena.

Deering's vocation is also his avocation.

He's collected butterflies for about 35 years. A small part of his personal collection (he owns almost 7,000 specimens) is part of a Butterflies of the World display at work.

"I've liked butterflies and other bugs since I was a kid in Kentucky, raising them, keeping them in my room. I enjoy what they do and how they act," Deering said.

He didn't know he'd be able to make a living from his hobby until he saw his first butterfly house in 1993.

"I was enchanted. I realized that, if I could have any job I'd never be bored with, it'd be that," said Deering, who holds a masters degree in entomology, the study of insects.

A visitor to the Butterfly House walked by, asking Deering how long butterflies live.

"It varies by species, but, on average, the egg takes 10 days to hatch. It's in the caterpillar form for about a month, in a chrysallis for two or three weeks, and lives five to six weeks as an adult," he answers.

Species are incredibly diverse, ranging in size, at the Butterfly House, from some birdwings and large owls that can have seven- to eight-inch wingspans to a glass wing with a half-dollar-sized wingspan.

Five butterfly farms supply shipments, every other week, of chrysalides (butterflies going through metamorphosis), from Costa Rica, Ecuador, Surinam, Malaysia, and, in the United States, the London Pupae Supply broker, that can provide butterflies from regions like Kenya, the Philippines and Tanzania.

A single shipment package contains more than 500 chrysalides.

"Last week, we got a total of 2,200 chrysalides and, over a year, we get about 50,000. At any time, we have 80 to 100 species in the conservatory, while, over a year, we'll have 200," Deering said.

After butterflies arrive, they're placed in an emergence case to be eventually released into the conservatory.

A butterfly's diet varies.

Deering pointed out hanging feeders with butterflies gorging on plates of banana, papaya, mango, pineapple and peaches.

Other butterflies landed to feed on conservatory plants like porterweed, pentas, tropical bloodflower and white leaf rondeletia.

With a butterfly garden outside, the Butterfly House even attracts local species. And it's home to more than butterflies.

The staff also raise beetles, praying mantids, arachnids, like spiders and scorpions, and other insects.

Deering feels fortunate to have the opportunity to work in "a facility considered by most in the field to be among the best in the world."

His boss returns the compliment.

"Mark is an asset to us because of his background in entomology and because he's so recognized by those in the field of captive invertebrate care," said Joe Norton, director of the Butterfly House. "And he's very personable for the average guest to interact with."

Watching brightly-colored butterflies circling overhead, Deering calls the job "one where I'm always learning something new."

"Butterflies are our 'bait and switch,'" he said. "We use peoples' attraction to them to get them here, to point out their similarities to other species of insects. We try to open their minds, so they realize not all spiders are out to get them, not all mosquitos bite, and not all bees sting."