With Mother Nature hinting at an early spring, undergraduates are looking forward to a warm Valentine's day full of kisses, chocolate and other tokens of love.

But this is an unusually difficult time of year for many of Harvard's security guards. For them, there's just too much loving going around campus these days.

February, they say, brings couples into Harvard laboratories, junior common rooms and lecture halls at odd hours of the day and night to consummate their desire. Happening upon a female and male undergraduate and a TF, or (on one notorious occasion) two professors in flagrante is one of the hazards of duty.

"I'll never forget the first time it happened to me," says one guard, who like all of those interviewed for this article, insisted on anonymity. "I opened up the classroom to lock up, and that's when I saw them. The first thing I said was: 'What the hell do you think you're doing?" But as soon as that was out of my mouth, I thought to myself, 'That's a pretty stupid question.'"

In fact, every one of the dozen security guards interviewed for this story say that have walked in on couples at least once in their security careers. These experts say common locations for lovemaking include classrooms and hallways in softly-carpeted Robinson Hall, bathrooms in all parts of the campus and large lecture rooms in some of the graduate schools.

"The funniest one I ever saw," recalls one veteran security employee, "was in this dumpster by the Kennedy School. I thought it was rats at first, but then I realized it was bigger than that."

Guards have noticed one important sexual trend--couples prefer first-floor rooms to higher altitude sites of lovemaking. "It's almost entirely first floor [classrooms and labs]," says a guard. "I don't know why not second and third floor rooms. Maybe when you're that hot and bothered, you can't wait to climb the stairs."

At times, walking in on young lovers can create some, uh, sticky situations, which aren't covered during the police department's annual sensitivity training seminars.

"What do I way in a situation like that?" asks one guard. "What can you say? I tell them to hurry up because I've gotta lock up. And I ask them to please turn out the lights when they're through."

Several guards say they have happened upon professors having sex with student's and one says he struggled with the question of whether to report the incident. Ultimately, he let it go.

"I don't know if it's supposed to be a thrill to find someone like that," says another guard. "I don't think it's too thrilling."

"It's not so much a student thing," he adds. "How can I say it...it's been people who have been in higher places."

Some of the higher-ups who have been walked in on have complained about peeping toms in the security guard force. A few years ago, gay students and administrators charged that Harvard officers were overzealous in the policing of the Science Center bathrooms, where some gays from within and without the Harvard community occasionally met to make love.

Stainless steel bathroom stalls in the Science Center as well as Emerson and Robinson Halls have since made sex in the bathrooms a chillier, more slippery endeavor, guards and police officers say.

Guards say they try not to impose on students and professors who want privacy, but they do receive frequent complaints about not-so-private lovemaking.