Talk about Teenage Mutant Ninja Turtle power. When it comes to the valley-talking heroes-on-the-half-shell, youngsters just can't get enough.

Turtle T-shirts? Awesome! Turtle sunglasses, turtle yo-yos, turtle fruit juice, turtle pizza thrower assault vehicles? Bodacious!

But when it comes to all the Dick Tracy lunch boxes, dolls and trading cards on shelves at area toy stores, the response from youngsterville has been far more tepid, store operators say. The stuff is gathering dust.

"Ninja Turtles {merchandise} is in a class by itself," said Vonnie Anderson, a manager at Lowen's Toys in Bethesda. "Whatever you get in Ninja Turtles, the kids buy right away." As for Tracy dolls, cups and figures, Anderson's pint-sized customers barely look twice. "I thought it would be a lot better," she said. "I'm a little disappointed."

It's summertime, the season of the movie blockbuster and the time when the adult gurus in Hollywood and on Madison Avenue roll out their latest attempts to win the hearts and minds of today's youngest consumers.

Last year, Batman was the runaway hit, with Bat toys and Bat clothes filling every Bat cave around.

But this summer, despite the avalanche of hype over the movie "Dick Tracy," the endless supply of Tracy spinoff products has been met with a resounding yawn from the collective critics who vote with their parents' wallets.

Sam Ratliff, 8, who was carousing through the turtles aisle of the Kay Bee Toy and Hobby store in Springfield Mall last week, is one who prefers turtles to Tracy.

"I like the way they fight and I like pizza and I like the way they talk," he explained. "The turtles are like ninjas, and most kids like ninjas and turtles, but not gangsters."

As Sam stood thoughtfully discussing his fascination, his cousins, Ruben Carvajal, 8, Chris Burns, 7, and Matt Burns, 6, were foraging for additions to their TMNT collections. "Awesome!" Matt exclaimed. "Turtle nightlight!"

In many ways, turtle heroes Leonardo, Michelangelo, Raphael and Donatello are the very models of today's youth: They love pizza, they talk in their own pseudo-valley-surfer-speak, they ride skateboards, they engage in rollicking fights in which serious injuries are rare, and they have a lot of fun.

Radioactively enhanced and ninja-trained, the heroic turtles have roamed the toy store shelves for 2 1/2 years and star in a weekday cartoon show. Based on their popularity, the live-action movie was introduced to the marquees in late spring, boosting the turtles to stratospheric heights.

So why haven't the kids latched onto Tracy as enthusiastically?

The answer may lie in birthdays.

Teenage Mutant Ninja Turtles emerged from the radioactive ooze in an obscure, underground black-and-white comic book by Kevin Eastman and Peter Laird in 1984.

Dick Tracy was born as the square-jawed copper in Chester Gould's legendary newspaper comic strip in 1931, and later immortalized in various serial shows in the 1930s, '40s and '50s.

Thus, both the turtles and Tracy match many of their fans in age.

"I think it's more the adults" who like Tracy, said Anderson, of Lowen's, "and I can't imagine an adult buying a doll."

As for the turtles, the adults don't always get it. When children ask mom or dad to give them three, some can't help asking, "Three what?" (Answer: Fingers. Mutant turtles have three of them to slap each other's hands.)

"Why they love them, we don't know," said Sally Carvajal, Ruben's mother, who carted the clan from their home in Quantico. "They're all toyed out on turtles," added Nora Ratliff, grandmother to all four boys. "They've got enough to start their own toy store."

Indeed, perhaps the people who already own toy stores should call the Ratliff house. Managers and owners say they've had trouble keeping turtle products on the shelves and equal trouble ordering replacements.

"Ninja Turtles way outsell anything. Anything Ninja Turtle sells," said Lisa Pyles, an assistant manager at K&K Toys in Herndon. "It's unreal."

John Hall, owner of Patowmack Toy Shop in Howard County's Columbia Mall, jokingly said he would trade six Tracy items for one turtle product, especially because Tracy toys seem to have bombed in his store.

"The parents look at them and say, 'Oh, Dick Tracy,' and keep walking," he said. "It's doing nothing. It's flat. It's slower than flat."

Not everyone is disappointed. Some report fairly brisk sales, at least of a few Tracy products.

Richard V. Sallis, senior vice president of Playmates Toys Inc., which produces toys for both lines, said Tracy toys are selling quite well -- better, in fact, than turtles when they were introduced in 1988.

But, he added, he recognizes that Tracy may not be the mega-toy success that the Ninja Turtles turned out to be. "Not everything can be a turtle."