Every day, the campus at St. Elizabeth’s Hospital plays host to a great many people — doctors, nurses, administrators, patients and technicians. But as the visitors bustle in and out, few notice the tiny creatures in their midst who call St. E’s home. They lurk in the shadows, skulk silently between the trees and dart out from under cars into the numerous hiding places that St. E’s’ expansive campus affords them.

They’re a colony of feral cats which has lived in and around the hillside site for several years. According to Lauren Kreisberg of Charles River Alleycats, the volunteer-run organization that feeds and monitor the animals, there are about 20 cats at any given time. She said that the number varies depending on how many kittens were born that year; how many cats make it through the winter; and whether or not any abandoned neighborhood cats joined the colony recently.

Last weekend, volunteers fanned out across the St. E’s campus, setting traps and attempting to round up as many of the cats as possible. Their goal is to neuter or spay them, give them a health check and vaccinations, then release them back onto the campus. They do this several times a year, usually in spring or summer.

Kreisberg explained that most animal rescue groups feel that this is the most humane way to deal with feral cats, which are largely un-adoptable. “We follow the ‘Neighborhood Cats’ model,” said Kreisberg, referring to the New York City-based animal-advocacy organization that developed the trap-neuter-return concept.

Cats that do not have any contact with humans by the age of about 4 months old generally cannot become used to them, she said. Instead, they are allowed to live out their natural lives in the place and way that they are accustomed, but are neutered in order to control the size of the population.

Since not all the cats can be caught on any given day, control, rather than elimination of the colony, is the name of the game. Last weekend’s efforts netted about 16 cats, a decent haul, according to Kreisberg. But some of the cats that were not trapped will continue to breed. “It’s an ongoing struggle,” she said. “If you miss one litter, you have to start all over.” In addition, more abandoned house cats will inevitably join the colony, which means that the volunteers’ work will continue indefinitely.

St. E’s has had a love-hate relationship with the cats over the years. Kreisberg said that in the past the hospital seemed to be somewhat hostile to the cats, but perhaps understandably so, since the cats brought fleas, feces and urine to the hospital grounds.

However, in more recent days, St. E’s has been actively helping the volunteer group to help control the cat population.

“We’ve been working with Charles River Alleycats on the humane trapping of the cats for about a year and a half,” said Melanie Franco, a facilities manager at St. E’s. “We are collaborating with them, and are concerned about the humane treatment of these animals.”

Kreisberg is pleased with this attitude, because she feels that a collaborative approach is the only one that makes sense for such an issue, no matter where you live. “Whether or not people like it, cats are a part of a neighborhood’s wildlife, and they should manage them as such,” she said.

In fact, the St. E’s campus is not the only place in Brighton were feral cats are an issue. Volunteers from Charles River Alleycats currently tend two other colonies — one in Brighton Center, and another based in a residential neighborhood on Surrey Street. They also look after colonies in Medford, Newton, Watertown, Cambridge and several other parts of greater Boston.

Kreisberg, who has been a volunteer with the Newton-based group for several years, feels that the more aware and educated people become about the issue of feral cats, the more success neighborhoods will have in dealing with them.

For more information about feral cats and to learn more about Charles River Alley Cats, go to charlesriveralleycats.org or call 617-244-0200.

Reprinted with permission. Copyright © 2006 GateHouse Media, Inc.