When the lights flip on in a room infested with cockroaches, they all jockey for the nearest dark hole. This is because roaches are nocturnal, says Gary F. Alpert, an entomologist who gauges and makes recommendations on University cockroach problems. "If you see them during the day, you know you've got problems," he says.

The German cockroach, blattella germanica, which are colored greenish-gold and grow to be an inch long, is the most common breed in Harvard dining halls, says Alpert. Darker roaches like the periplaneta americana and Oriental blatta orientalis are found outside kitchens in places that includes student rooms, he adds.

Although unpleasing is appearance, the cockroach once inspired a poem from post-modern novelist Christopher Morely.

Timid roach why be so shy?

We are brothers, thou and I.

In the midnight like thyself

I explore the pantry shelf

Alpert sometimes uses "The Cockroach Combat Manual", where Morely's poem was found, for reference, This humorous 180-page paperback cities that cockroach fossils date back 350 million years, But, since no North American have been found, that orgin here is unclear, says Alpert.

The popular story that cockroaches can survive a full-scale nuclear war has no scientific basis, says Alpert adding that "roaches are more resistant to radiation than people," but they would not likely live through intensive nuclear radiation.

Because they are natural food scavengers, roaches prefer to live near kitchens and other food areas. All breeds, except the Oriental cockroach, thrive in warm temperatures--around 30 degree celsius. The German roaches live best in warm climates, but most other breeds prefer damp areas like sewers,

Although not disease carriers themselves, roaches have been known to carry disease-ridden bacteria that causes diarrhea, dysentery and food poisoning. Benjamin H. Walcott, assistant director of Harvard food services, says then try alleviate roach-intimated disease through pest control. But Walcott adds that public concern about rather than the health hazard they pose.

"They run so fast and they conjure up connotations of dirt he said.