NORTH KEY LARGO -- A local wildlife refuge is expecting a most unusual delivery early next year from Disney World: 10 rats.

For almost four years the Disney Wildlife Tracking Center in Orlando has been breeding captive Key Largo woodrats with hopes of releasing the endangered forest-dwellers into their native habitat to regenerate the local population.

The irony of a large corporation built around a cartoon mouse working to save a rat on the brink of extinction has not been lost on the Disney scientists.

"We're not Mickey Mouse-ing around," quipped one scientist who asked to remain unidentified, not due to the bad pun, but because he is not the program's director. The director cannot be reached until after Christmas.

Steve Klett, manager of the Crocodile Lake National Wildlife Refuge, and volunteer brothers Clay and Ralph DeGayner, have been busy building woodrat nests in a 10-mile stretch of hardwood trees along County Road 905 in anticipation of the Disney delivery.

The nest sites are built of concrete blocks, arranged so the cages of the 10 woodrats to be released will fit inside for a comfortable transition from captivity to release.

"They'll plug their nest box into ours," Klett said last week. "One [cinder] block will be replaced with a food and water station that allows for a constant food supply. We'll provide a commercial chow supplemented with lettuce and other natural foods.

"They feed on a variety of local trees and shrub berries and nuts as well as leafy vegetation," he said. "We don't know how critical this aspect of the project is because of unknown behavior so we'll be tweaking the food allotment as we go."

Resident woodrats (Neotoma floridana smalli), known for building large stick houses out of native vegetation, have taken a liking to previous artificial nests built by Klett and the DeGayners.

In fact, one of the receiving nests had already attracted a local resident last week. Nearby, built into the upturned roots of a fallen tree was a second nest.

Much like Mickey, Key Largo woodrats are not your stereotypical rodent.

"These guys live in trees, not in your home," Klett explained. "They are not exotic Old World rats that become pests. They don't smell and have a very soft coat and a shorter tail, more like a mouse. They are also much more laid back."

Klett says previous efforts to establish a woodrat colony outside of North Key Largo have failed. He is cautiously optimistic about the prospects of the captive-bred group eventually adding to the local gene pool.

"It can't be as simple as putting out supplemental structures. But it's very simple science," Klett said. "There are three components to a wildlife habitat. The woodrats need food and water, cover and a place to reproduce. We are providing two of the three."

Female woodrats can produce two litters a year and each sex requires about five months to reach maturity.

"Fifty years ago we found woodrats from Tavernier to Ocean Reef," Klett said. "Now that habitat has shrunk and every single animal is important."

sgibbs@keysnews.com