When River House dwellers returned to campus this past week, some found more than the standard- issue desk and bookshelf waiting for them in their rooms.

Cockroach sightings, seemingly concentrated in Eliot and Lowell Houses, have prompted numerous visits to undergraduate rooms by University-employed exterminators and have left some students feeling nervous about these unwanted guests.

Laura P. Humber '02, a resident of Eliot House, said she started screaming when she saw roaches climbing out her drain after turning on the shower.

"They were large and brown," she said. "We threw my roommate's Steve Madden boots at them."

Harvard's bug czar is Gary D. Alpert, who carries the more formal title of Entomology Officer of Environmental Health and Safety.

Alpert says these visitors are standard American cockroaches. They gain access to dorm rooms, he said, in the summer months when shower pipes are dry and the roach can climb up through the drain.

Usually, plumbing systems contain a "water trap," a kind of moat where water collects in a curved pipe. Normally, cockroaches can't cross it, but in the summer months the water evaporates and the roaches can get inside.

When newly arrived students turn on their shower for the first time, they might be greeted by roaches who have made their home in the pipes and are being forced out by the running water.

Alpert says once occupants start taking regular showers, keeping the drain wet, the cockroaches will disappear.

Some Houses took steps to run the roaches out before students arrived.

"Before the students arrive, we clean the drains and apply a cleaning

compound," said H. Joseph O'Connor, Dunster House superintendent and building manager in the Houses. "It tends to drive [the cockroaches] down, otherwise it would have been a bigger problem. If we hadn't treated the drains, there would have even more."

While O'Conner's efforts seem to have paid off--he's gotten only three

roach-related complaints in Dunster--Eliot House has had roughly 18 of its rooms treated for cockroaches by Best Pest Control, Harvard's exterminators.

Eliot's new superintendent, Francisco Medeiros, declined to comment.

Rod J. Kreimeyer, owner of Best Pest, says cockroaches can appear in any room where the pipes have dried up and will not necessarily be confined to a specific floor or entryway.

Though close to two dozen Eliot rooms were treated for roaches, Kreimeyer says, ""Off the top of my head, I would say that there were not more calls than last year from Elliot...[this is] nothing

unusual."

Kreimeyer says the University as a whole has been proactive in working to prevent infestation problems, sighting efforts to chemically treat basements, mechanical rooms and crawl spaces as a way to keep the cockroach population from burgeoning.

"The problem is minimal to what it used to be," he said. "The cockroach

problem is almost eliminated."

But for some students, close encounters of the six-legged kind are very real. Mary E. Unsworth '01 of Lowell House had to throw out all her toiletries after finding close to 10 cockroaches in a bag in her bathroom.

"Cockroaches are very rare once the building is occupied," Lowell House

Superintendent Jay Coveney said. "When the students are here, it's no problem, unless they are really

filthy and never take a shower, and the drain dries out and they [the cockroaches] can come up."

In an effort to prevent cockroaches from taking over a room during the school year, Kreimeyer suggests students pay special attention to keeping their rooms clean, leaving no dirty dishes out and rinsing out bottles before they get thrown into the recycling bin.