The praying mantis is the only insect that can turn its head.

Earthworms have "bristles" they use to try to hold themselves in the ground when robins tug them out. And earthworms, by the way, do not belong here. The non-natives were carried here, mostly from Europe, by fishermen and imported soils.

These are the types of factoids that emerge when a collection of college biology professors descend upon a Quad-City nature preserve.

The 350-acre Green Valley Nature Preserve in Moline was at the center Saturday of a bio-diversity day, which sent scientists and their volunteers into the woods and watersheds in search of bugs, birds, plants, amphibians, even earthworms. The goal was to get a basic inventory of the species present in the habitat.

Teaming up with the group was River Action, which is in the process of restoring a wetland area between Moline's softball complex and the Rock River.

Amy Blair, a biology professor at St. Ambrose University, Davenport, spent several hours Saturday morning trying to coax worms out of the drought-hardened ground. She took her two gallons of water and package of dried mustard seed into right field of one of the baseball diamonds at Green Valley, hoping the irrigated ground would produce better results.

With her young assistant, Ismael Chambers, she poured the dried mustard seed into a gallon of water, which she poured onto the ground. Mustard seed burns earthworms' skin, which, along with the water, encourages them to move to the surface. But the worms weren't biting.

She ultimately captured just one worm, which she found near a creek bed.

Placing the worm on one of the microscopes that were set up on a picnic table, Blair and Chambers took turns counting the number of "sections" from its head to its clitellum, which is part of its reproductive system. An earthworm guidebook then helped identify, by the number of "sections," the species of worm.

"I counted 24 from the head to the bump," Chambers announced, before counting again. "Actually, I think I count 28."

Blair also counted 28, declaring it a leaf worm.

She explained other earthworm details, such as the fact they are both useful and potentially harmful to your gardens at home. While their movements help aerate soil and also prevent it from clumping, earthworms also eat dirt, sometimes consuming plant seeds, too.

Meanwhile, another group came out of a wooded area of Green Valley, carrying nets over their shoulders.

Tierney Brosius, an entomology professor at Augustana College, Rock Island, carried part of the insect bounty, which included two healthy looking praying mantises.

"I'd like to take them to class, and I'd like to keep them alive," she said. "They're much more interesting alive."

Michael Reisner, director of the Upper Mississippi Studies Center at Augustana, said he hoped the day of study would produce a preliminary map of the "hot spots" in the preserve for various plants and animals.

"Next time, we'll get some counts — understand the abundance," he said. "We'd like to know the dominant species. You don't want the invasives dominating."

Ultimately, he said, an inventory would help guide future wetland maintenance plans and conservation efforts.

Kathy Wine, executive director of River Action, pointed out the group also is interested in what happens in Quad-Citians' yards and not just in large parks and preserves.

"For instance, just look at tax assessments, and you'll see that homes along urban forests (ravines) have higher values," added Reisner. "These kind of habitats also improve people's attitudes. They are happier, living among the canopies and near wildlife."

In fact, a sociology professor also was part of Saturday's team, looking into the attitudinal effects the area has on humans.

"It's truly an interdisciplinary effort today," Reisner said.

Back at the microscope, Blair continued her assessment of the day's lone earthworm.

"Some burrow deep, others feed off the surface, and some never go underground," she said. "Minnesota is interesting, because they shouldn't have any earthworms at all. Discarded fishing bait accounts for a lot of it.

"The classic night crawler, the big one, is from Europe. Some worms are one inch long and never get bigger. When it gets this hot, some go into estivation, which is like a mini-hibernation. They go way down deep and take a snooze."