Craig Phillips has roaches in his house. It's alright. They're invited.

" realize most people would have few positive things to say about roaches," said Phillips. "I think they're just marvelous insects. They seem to have so much personality."

Phillips is a biologist. When not observing the 14 species of exotic cockroaches he raises in his Silver Spring home, he is also director of the National Aquarium.

His wife Fanny, also a biologist, shares his interest in unusual insects and animals. And that's a good thing, because, in addition to the roaches, the Philllipses raise 12 snakes (pythons and boas) two possums and about 13 tarantulas.

"We tend to go for unpopular causes," said Phillips. If certain animals have been maligned, "we feel we want to get to know them."

Everyone loves butterflies with their graceful form and color, and many people have collected and studied them, said Phillips. That, he explained, is why he will never have a butterfly collection. Raising the less popular cockroaches, on the other hand, allows Phillips to "explore territory that hasn't been quite so thoroughly covered."

The Phillips roaches are not, mind you, the "German" variety of domesticated roaches that commonly infest houses in this part of the country. His roaches come from places like Brazil, Cuba and Africa. Some are so . . . well, so pretty it's hard to believe they're actually related those hateful bugs you can't seem to keep out of your kitchen.

All 14 species live with their kin in separate terraria kept in Phillips' study. There are roaches that hiss and roaches that smell and roaches that squeak. There are roaches that look like fire-flies and roaches that look like beetles. There are even roaches that look like they have faces painted on the back of their shells and there's one species whose color and shape look sort of like a violin. Phillips calls one of the species the Stradivarius.

And they're not all brown and ugly. there are the brilliant green banana roach, the black and brown checkerboard roach and the beautiful three- inch -long Giant Blaberus whose shiny, irridescent shell is a brwonish-silver color.

Phillips says roaches are not aware of humans -- "I don't think they'd know me from anyone else." But they do get alert at feeding time and Phillips finds their behavior "just fascinating." He likes to see them scramble for the food and "twiddle their anatennae" -- the locus of their senses of taste and smell.

While they are interesting, Phillips admitted he can't really tell his roaches of the same species apart.

"Individuality is practically lacking from roaches," he says. In some species you can't even tell the male form the female, he added. A person who raises roaches cannot be concerned with individual personalities -- you have to look at them more like a coin collection, said Phillips.

Besides, who says a pet has to show affection, or even recognize you, asked Fanny Phillips.

"Why is it always necessary that pets show affection and show dependency? This has to do with a human need and is irrelevant to the animal," she said.

Raising cockroaches is not without its problems. The roaches have occassionally escaped but the Phillipses have always recovered them. Unlike domestic roaches, the roaches from the collection aren't good at finding scraps of food, explained Phillips. When they're ready to eat they come out in the open, he said.

There is also the problem of overpopulation, caused by the roaches' fast breeding tendencies.

Phillips solves that one by freezing the surplus roaches -- it's the most humane way, he insisted, much better than flushing themdown the toilet -- and then feeding them to the possums. "They love those fat roaches," he says.

And once in a while domestic roaches -- yes, the Phillipses have a chronic-problem in their kitchen, too -- will make their way to the roach room. But that doesnT happen often enough to cause any real problems.

The Phillipes say their Silver Spring neighbors have never complained about their unusual pets.

"The neighbors know us and they know we're conservative and responsible, " said Fanny Phillips. After all, her husband added, "we're not Barnum Bailey."

They did run into one problem many years ago when they lived in Miami, the Phillipses remember. A "strange man" who assumed they had poisonous snakes, tried to make trouble, Phillips recalled.

When the Phillipes discovered the man was spreading false stories about them, they invited the police over to check out their snakes. The police came by and, satisfied there were no poisonous snakes on the premises, became very interested in the Phillips' collection.

"They wanted to know when we were going to feed the python," Phillips remembers.

A few evenings later the Phillipses decided to give a party for the police department. During the party the police and their wives were "introduced" to the snakes and at the end of the evening they all watched the Phillipses feed a chicken to the python.

They left on a friendly note and after that there was never any trouble.