The "song" of the 17-year cicada has crescendoed to the proportions of a "din," or at least a "racket" in Central Maryland; cats and dogs are snacking on them like potato chips and their discarded shells and rotting bodies are piling up.

If all this is driving you buggy, experts say, about all you can do is turn up the stereo, sweep the walk and wait them out.

"I think it's peaking right now," says Gaye Williams, a Maryland Department of Agriculture entomologist, who is in the throes of a certifiable love affair with the insects.

"The volume in my yard went up Saturday morning, like they had kicked in the big speakers," Williams says, confessing to having audiotaped the cicadas' noisemaking and to shooting eight rolls of film of their transformation from nymphs to winged adults.

"I'm totally intrigued," she admits. She even plans to videotape their mating ritual in a sort of cicada-porno movie.

Sex, after all, is what all the noise in the treetops is about. The male cicadas are frantically calling to the females, desperate to mate before their biological clocks – with only weeks to tick – run down.

Cicada-phobes may want to listen from a well-screened porch, but if you don't mind cicadas landing on your shirt or crawling up your leg, Williams insists you can learn a lot by joining the cicadas in the yard.

First, pick one up. If it protests with a buzz, it's probably a male. Under its wings, you'll see a small white circle about where you would expect its kidneys to be. That's the tymbal; the cicada vibrates it with muscles. That – multiplied by the millions – is what makes all the noise.

Marylanders are describing the cicada's love song in bewildering variety. Some say it's a high-pitched warble that sounds like the landing of a flying saucer in a grade-B movie, or an urgent, midrange rasping like some kind of out-of-whack machinery.

The variety in the descriptions, Williams says, is probably because there is not just one, but three, species of 17-year cicadas out there, each trying to be heard over the others.

The largest in both size and numbers is the Magicicada septendecim. He's the one making the constant flying-saucer sound. The adult is distinguishable – barely – by a brown plate between the base of the wings and the eyes.

The second species is the Magicicada cassini. "That's the one that has the shrill sound, like a horde of parakeets. It's much louder than septendecim," Williams says. It is distinguished by solid black plates between wings and eyes.

The third species is Magicicada septendecula, which also has the solid black plates, but has a striped belly to distinguish it from cassini. Williams believes their song may be the ticking noise she had heard in the treetops at noontime.

What the cicadas are busy doing now is sorting themselves out by species, Williams says. Alternately calling to the females and flying out from the trees, the males are locating the females and congregating by species in certain trees, or parts of trees, for mating.

"Fortunately, the bugs know the difference," Williams says. "I have to identify them just when I get ready to off them."

The mating ritual itself is not unlike that of humans, apparently.

Says Williams: "The female is cool to the whole thing. The male extends his closest front leg and they end up back-to-back."

The cicadas' song, generally, lasts from dawn until dusk, although a few individuals can be heard squeaking or singing "phaaa-roah, phaaa-roah" in the low bushes anytime during the night, Williams says. And a loud noise, such as a car ignition, may stimulate a competitive chorus from nervous males in the area.

But, ever protective of the cicadas, Williams declares their nighttime vocalizing is "not as obnoxious as some mockingbird getting up at 3 in the morning."