Robert L. Birch, an Agriculture Department Librarian, was passing out his card, which asks, just above his embossed name, "Can a Bee Resting?"

You were supposed to make the mental leap to recognize that "resting" could be read as "re-sting," thus making sense out of the question, if not the visiting card.

Birch was beaming with confidence in those taking his test. After all, the occasion was the weekend's regional gathering of the local Mensa - the national club which requires high scores on standard intelligence tests for membership - of which he is a member. More than 200 Mensa members attended the three-day gathering at Stouffer's National Center Hotel in Crystal City, Arlington.

There are more than 25,000 Mensa members in the country, and 900 in the Washington area. To join, they must do well on a Mensa intelligence test, or produce results of other such tests, - college boards, Stanford Binet, Wechsler, for example - which prove that they are among the top 2 per cent of people tested. It is the equivalent of about a 130 I.Q., or above, on tests where normal is 90 to 110, and "genius" is 172.

The convention was entitled "intelligence Comes to Washington" - and whatdid they do? Watched porno movies from 1 a.m. to 4 a.m. Checked their futures on Tarot cards, Ouija Boards and the reading of palms. Played board games. Attended "a satanic ritual, conducted by MWM's (Metropolitan Washington Mensa) Resident Witch."

"If you think we came down here to listen to a bunch of lectures, you're crazy," said Harper Fowley, an architect from Louisville, Ky., and second vice chairman of the organization. "We came to see our friends. I plan to drink a lot of wine and eat a lot of cheese."

"It's intended as a fun weekend," said the national chairman, Charles Fallon, a management consultant from Chicago.

"It's specifically geared away from intellectual activities, which might strain the attention span of most of the members," said Charles Condon, a psychologist who administers Mensa tests to prospective members every month. "It's not too much different from other social organizations."

Why not? Why don't Mensa members have more intellectual interests than the 98 per cent of the population which tested as having lower intelligence?

"Because intelligence ain't that much," said Joseph McLellan, the Washington group's Local Secretary and an assistant editor of The Washington Post's Book World. "Intelligence tests. These are people who have large vocabularies and are good at algebra and logic.

"The point is not, who's qualified to join, but who does join. Most eligible people have no need to, because they have made their peace in the world. If you are at the Brooking Institution, you can get good conversation at lunch. Generally, the active member is in an environment which doesn't satisfy his needs or exercise his abilities to the utmost.

"They tend to be white government employees and computer technicians, with a few teachers and librarians."

Many join simply to have the certification that membership represents, he said, but for the active members there are 20 or more events each month - lunches, parties, Scrabble games, poker charades.

"It's the best social club in the world," said David Humes, a Coast Guard intelligence investigator who is regional chairman. "I'm dumb on electronics, but I can always find a friend here to check something out with, and I'm a word person and can tell him what to read."

"I've been a housewife for 28 years; in various places, for 28 years." said Pat Rawnsley, who now lives in Warrenton, Va. "If I go to a party, the men are all bunched up at one end, talking sports and cars, and the women are yakking at the other end about children and the PTA.

"If I try to talk about anything like what's going on in the world, it's a real conversation stopper. To be tolerated, I have to keep my mouth shut. Here I can spend a whole weekend with people who understand everything I say."

Fallon, the national chairman, added that "Mensa gaves you the freedom not to know what someone's talking about - to ask dumb questions. You don't have to be afraid of falling on your face and looking like an idiot, because you've got a piece of paper which says you're not an idiot."