WHETHER students and Harvard administrators want to admit it or not, nocturnal observations and dining experiences over the past two years have convinced me that several University dining halls face a serious and potentially hazardous infestation by large, disease-carrying rats.

Episode One: (a lonely Monday morning, 2 a.m., October 1987, Winthrop House dining hall). While working on a Statistics 100 problem set, I gradually wake up to the reality that a large, grey rat (about the size of a fat guinea pig) is peering down at me from the nearby Coke machine. After a near miss from a No. 2 pencil, the rat hastily scampers behind the machine and out of sight. Although I will probably never know whether the two events are connected, about a week or so after this encounter, the Winthrop House Coke machine is out-of-order for several days.

Episode Two: (November 1988, Winthrop's Standish courtyard, about 1 a.m.) While heading home after a long night of studying in Winthrop's house library, I am greeted on the sidewalk by what I initially think is a squirrel. A quick second look at a long, hairless tail convinces me that this rodent, now running for the bushes, is no innocuous squirrel, but a well-fed rat.

Episode Three: (January 1989, Winthrop House dining hall, lunch). A pretty cold day, so I opt for the clam chowder. Wrong move. As I go to open my package of S.S. Pierce Saltines my friend points out the very appetizing fact that it has little rat-sized bite marks. I give the crackers to the dining hall checker who promises to bring it to the attention of the proper persons.

MORE recently, my night-owl habits that often bring me to the Winthrop dining hall have brought me into more frequent contact with Harvard's rat community. The record for simultaneous observation now stands at three: one on the Coke machine and two on the conveyor belt for dirty trays. The scary thing is that where the rats once ran at my presence, they are becoming bolder with each passing day.

According to Joe Niccoloro, a Senior Inspector with the City of Cambridge, all 25 Harvard dining hall recently passed the twice-annual inspection which is required by law. Niccoloro admitted that there is an infestation problem at a number of these places, but stressed the fact that this is a problem all over the Back Bay area and that Harvard is making progress with control, making that a "number one priority." He noted that the city has the power to close down any food establishment within city limits which is "overrun" by an infestation problem--but "that depends on tabulation."

I talked to dining hall personnel at Winthrop and Eliot who echoed similar views. They admitted that there is a rat infestation problem--not only at Winthrop but in many other dining halls--but pointed out that exterminators visit the dining halls once per week.

Yet, at least at Winthrop House, (where food personnel told me that they frequently open up in the morning to find rats walking across the grill) the feeling is that the University's and the exterminator's control measures are far from adequate: "I don't know what poison the exterminator feeds them, but they just keep getting bigger." At Eliot House, the sentiment is that for some unexplained reason the rats have recently been "more active" than normal.

The presence of rats on such a scale poses a serious health threat. Rats--carriers of disease and disease-infested parasites--are viewed by health officials as a serious health hazard. In New Hampshire, where my parents own a restaurant, health officials would have ordered Winthrop's dining hall to close until the rat problem was eliminated or at least placed under control.

Contrary to what city and Harvard officials might say, having rats running on grills, salad bars and areas where dishes are washed does not represent a rat infestation problem under control.

INDEED, several Harvard dining halls--certainly Winthrop's--are sitting on what are essentially festering rat nests. Harvard officials have not addressed this serious problem and potential health hazard effectively. Having a weekly visit by an exterminator is not enough--especially when it is clear to service personnel and residents alike that the problem is becoming more acute rather than subsiding.

So far the Harvard community has been lucky that rats on grills and salad bars have not led to any serious health problems. But this is a health gamble Harvard should not continue much longer. Closing the dining halls with the most severe infestation problems may perhaps be a bit of an overreaction at this point (perhaps not), but the upcoming spring break affords Harvard with an excellent opportunity to finally address a problem it has not largely skirted so far.

Harvard should see to it that 1990 is not the Year of the Rat--again.