On weekdays, Dennis and Carole Moore are mild-mannered employees of the Government Printing Office. But on weekends, they take off their Clark Kent-type glasses, put on costumes and load their van with mysterious trunks and bags containing creatures most mild-mannered people wouldn't touch with a 15-foot pole - snakes.

Not only king snakes and garter snakes, but pythons, cobras, boa constrictors, copperheads, even rattlesnakes. And the people who wouldn't touch the snakes come to see them co-star with ihe Moores in a show called "Snakes Alive," which packs them in regularly at area parks and libraries. During the show, one volunteer - invariably a kid - not only gets to touch a snake but gets to hold a 100-pound, 15-foot long reticulated python named Venus by the tail.

When not performing, Venus and her buddy, Thor, live in floor-to-ceiling, glass-enclosed, specially-heated terrarium that takes up a large percentage of the recreation room in the Moore's townhouse in Centreville, Va. A fiberglass fountain, a pool, and a rainforest mural recreate the environment of the snake's Southeast Asian habitat.

"We used to have hanging plants in there, but they pulled them down," says Carole, who married into the snake-handling business about two years ago. "At first, I never thought I'd be able to touch snakes."

Dennis Moore, somehow, grew up without accquiring an aversion to snakes. He had his first encounter with a snake when he was about eight, and it was a positive encounter.

"We were driving along, and my father saw a snake in the road and stopped the car. He picked the snake up and showed it to me, then let it go. It was exciting," Dennis recalls. "Later, I found it even more exciting that when I picked a snake I drew a crowd. I started with a brown king snake, then moved up into boas and pythons. I was nobody until I was the kid who had snakes. I'm still basically a show-off. I love to hear people ooh and aah."

Moore is not a herpetologist, though he has read "just about every book about snakes I could get my hands on. I have no scientific background - just a genuine love for the animal."

Most people get their genuine aversion for the animal straight from the Bible, Moore feels.

"A snake led Adam and Eve astray. Then there's the fact that some snakes are poisonous, so people would rather hate all snakes than learn which ones are poisonous. In this area, there's only one poisonous snake - the copperhead. At the shows, we tell people this and try to get kids to recognize its butterfly markings."

At a recent show, Dennis was bitten by a copperhead, but went on with the act.

"My finger swelled up, that's all. The last person to die from a copperhead bite died in 1956, and I think he was anemic," says Dennis. He does keep antivenin on hand in case of rattlesnake bite, however.

"Now that we have Cleopatra, we'll have to get some cobra antivenin," says Carole. She removes a television set from the top of an innocent looking wicker trunk so Cleopatra, a king cobra, can be introduced.

"Come on, girl," urges Dennis, taking Cleopatra out of the trunk using a long pole with a hook on it. He grabs the 11-foot snake by the tail, and she writhes around the room making a sound that's a cross between a hiss and a growl. Then she makes an arch like a swan's neck and points her face at us, baring venomous fangs.

"She's threatening," explains Dennis, "When they strike, they fall to the ground. Cobras are among the most poisonous snakes, but they're not the most dangerous because they're very slow."

Cleopatra is the latest addition to the Moore's collection of "thirty something" snakes. All of them lived with the Moore's until recently when most went on permanent exhibition at a pet shop in between shows. Venus and Thor, bowever, remain at home because they're special pets.

"They're fascinating to watch," says Dennis. "Snakes are pets like fish are pets. They're not pets you hold on your lap, but they all have their own personalities. They're very independent and majestic and they command respect. Even rattlesnakes are sort of lovable in a way. In the show we tread a fine line between making the snakes look adorable and emphasizing that some of them are dangerous animals."

Not every snake performs in every show.

"We have aquantity of each type," says Dennis. "If we used the same snakes every time the trauma of being picked up could cctually kill them. Also, they'd get too tame. When rattlesnakes lose their fear of you, you can't milk them."

In the show, Dennis holds a rattlesnake by the neck and rubs a certain spot, which makes the snakes eject some venom. This "milking" is just to show the audience how it's done. But snake venom obtained in this manner is used by pharmaceutical firms to make antivenin.

The snakes, however, aren't trained like circus seals. "Whatever they do naturally, I use as a trick," says Dennis. "Venus, for instance, is ticklish. I tickle her and she jumps back in her box."

The Moores hope their shows will help ease people's fears of snakes - fears that make some friends refuse to come to the Moore home and which prompted some of their neighbors to get up a petition against their pets. The Moores believe such fears are unfounded, as long as you take proper precautions and know how to handle the animals.

"Ninety-nine percent of the people who comes to our shows feel better about snakes when they leave," says Carol. "If we can change people's minds about snakes, all animals will be a little better off."