It's like something out of a science fiction movie: red-eyed invaders from underground overrun Washington, DC! All around the nation's capital, and all across the northeastern United States, insects the size of your thumb have emerged after nearly two decades underground.

These 'periodical' cicadas are filling the air with their eerie call. But, when you hear the droning, don't think science fiction. Think romance.

It happens every 17 years. On some mysterious cue known only to them, billions of red-eyed cicadas crawl up from underground and take to the trees, shedding their exoskeletons on the way. Some places may see up to 250,000 per hectare. Empty shells litter streets and sidewalks, leaving the ground crunchy beneath your feet.

Creepy, maybe. But harmless. The worst these bugs do is lay a few eggs in the bark of young trees. Okay, a few hundred eggs. But most trees can take it. Maryland homeowner Carol Nelson's yard is full of cicadas. But she doesn't mind.

"I'm fascinated by them. Every night at midnight I come out and look at them. Because they're everywhere. Last night was the biggest night so far we've had. And they're really all over the place. It's louder today than it was yesterday," she said.

That otherworldly drone that's reverberating across the Northeast is the start of a remarkable mating process. Entomologist Mike Raupp of the University of Maryland says the buzz lets the "girl" cicadas know where the "boys" are.

"This is basically a big boy band up in the trees. It's only the male cicada that sings," he said. "The deal here is, these guys are saying, 'Hey, c'mon up here, it's over in this tree, the big party's over here.'"

Once the males and females have met up in the treetops, Professor Raupp says the 17-year cicadas are surprisingly romantic bugs. They look each other in their big red eyes. Then the male will sing three songs to the female to try to woo her into letting him father her nymphs.

"The first one is sort of like, 'Hey, come over here. Can I buy you a drink.' The second courtship song is, 'Well, where do you work? What do you do? Where are you from?' Breaking the ice, getting to know you a little bit. And the third one is, 'Hey, after it's closing time, do you want to come back to my place, maybe, and look at my etchings?'"

And if he's won her heart, they'll mate. A week later she'll lay her eggs in the bark of a tree. A few weeks after that, the eggs will hatch. The young will drop to the ground, burrow into the soil, and they won't come up again for another 17 years.

Each time the cicadas make their appearance, Professor Raupp says it's a bonanza for any bug-eating creature.

"Look at this poor guy. A bird got him this morning," he said. "Tore off his wings. Ah, this is a girl," he said. "Ate the abdomen full of nutrient-rich eggs and just left the poor carcass behind. So the mortality on these things is just spectacular right now. It's a real scramble for life."

Birds, squirrels, foxes, even other bugs like beetles and spiders are feasting on 17-year cicadas. Homeowner Carol Nelson says even the goldfish in her outdoor pond is eating them. But the birds are really enjoying them.

"Some birds or something had a great time with them," she said. "It was like a buffet. Yeah, it was definitely all you can eat. More than they can eat, I guess," she said.

And that's the key: Professor Raupp explains the cicadas all emerge at the same time so there will be more around than the predators can eat.

"Their strategy is to simply overwhelm the predators by numbers. It's a sort of a safety in numbers game they play. The predators will be so fat in the next week that they simply won't be able to consume any more periodical cicadas."

Not a terribly crafty strategy, but it seems to work. One predator the cicadas won't have to worry much about is people. While insects make up a substantial portion of the diet in many other parts of the world, Mrs. Nelson's daughter Sara sums up the attitude of most Americans:

"I would not eat them, I'm not happy about other people eating them, I think it's disgusting," she said.

But Mike Raupp disagrees. He's been taking advantage of this rare event to try all kinds of cicada delicacies. "We've had boiled cicadas, fried cicadas, stir fried cicadas, cicadas Shanghai, cicada gumbo," he said.

It's a versatile insect that takes on the flavor of whatever it's prepared with. Professor Raupp is joining a Japanese film crew later today to make cicada sushi. And then there's a French-inspired dish called cicadas en croute.

"A little puff pastry, cicadas gently sauteed, with root vegetables turnips, carrots because they feed underground," he said. "And this is all put together in a little pastry, baked, and they were delicious."

Sounds like a gourmet dinner, for a bug lover at least. And what better way to enjoy it than accompanied by the romantic call of the 17-year cicada.