Grade: C+

There’s really only one way to see this new computer-animated feature from John A. Davis, the maker of “Jimmy Neutron: Boy Genius,” and that’s in the 3-D process in which the movie will be shown in IMAX theatres. The visuals of “The Ant Bully,” which look flat and rather dull on an ordinary flat screen, literally pop out at you in the 3-D format, and give the picture a surface pizzazz it lacks in content.

That’s because in terms of story, the movie is wan and derivative. Based on a children’s book by John Nickle, it’s about a short, lonely suburban boy named Lucas (voiced rather shrilly by Zach Tyler Eisen), who’s bullied by a big neighborhood kid and in turn takes his frustrations out on the ant colony that makes its home on his parents’ front lawn. When his mom and dad (Cheri Oteri and Larry Miller) go off on vacation and he’s left in the none-too-tender care of his goofy grandma (Lily Tomlin), an alien-invasion freak, and his “whatever” teen sister (Allison Mack), Lucas is shrunk down to insect-size by the colony’s sorcerer Zoc (Nicolas Cage) and taken into the anthill, where the wise queen (Meryl Streep) decides he should be instructed in their way of life under the tutelage of kindly Hova (Julia Roberts), Zoc’s girlfriend, and the more imperious Kreela (Regina King), who’s being romanced by smug but stupid scout ant Fugax (Bruce Campbell). Ultimately the literally little Lucas learns, as Hova puts it, to find his inner ant–that is, to work with others rather than shut them out, and thus achieve goals that will be beneficial to all. He helps out against an assault on the ants by their natural enemies, the wasps, and then persuades the wasps to join forces with the ants against a common foe–a ruthless exterminator (Paul Giamatti) he himself had been tricked into hiring before his miniaturization. On the other hand, Zoc, who’s initially skeptical about the possibility of taming the boy’s destructive impulses, comes around and saves the kid after he’s been swallowed by a hungry frog (though one may wonder how a frog-infested pond suddenly appears in Lucas’ front yard). In the end, of course, the boy is restored to proper size with a new attitude and, through collaboration with other neighborhood shrimps, turns the tables on the bully who’d been tormenting them all.

There’s nothing wrong, of course, with a message directed against bullying and in favor of teamwork. Situating it within the context of an ant colony–a highly regimented, one might say mindlessly despotic–community seems a mite strange, to be sure; compare the vision in 1998’s “Antz,” in which individuality was an act of rebellion against the colony’s gruesomely controlled society. (One might imagine a follow-up in which a kid is taught “the way of the termite” as a means of urban renewal.) But the ants here are a highly sociable sort, with personalities hardly indicative of mindless obedience, so the problem is muted. Aside from that, though, the plot isn’t exactly ground-breaking, if you’ll pardon the pun, and the lead characters aren’t terribly likable, with Cage’s Zoc, Eisen’s Lucas and Campbell’s Fugax more strident than endearing and Roberts’ Hova simply pale. (Streep, meanwhile, has little more than a cameo, and though it’s amusing to hear Ricardo Montalban’s voice coming from an ant elder, he’s got little to say.) On the full-sized human side, Tomlin’s turn as grandma, who periodically loses her false teeth, isn’t very funny, and Giamatti does surprisingly little with the exterminator role, which anyhow seems a retread after “Over the Hedge.” As is usual these days, there’s also an excess of the humor involving flatulence, excrement and other forms of glop that’s mandatory in contemporary kidflicks, it seems, but no less lamentable for that. And what’s the deal with the huge derriere on Lucas’ mom? Even your average bowling pin looks svelter.

But if there’s little that’s inventive or genuinely touching in its script or characterization (apart from one memorable moment involving a firecracker, which we see about to go off from the ants’ perspective and then exploding rather punily in a wide shot), visually the 3-D version of “The Ant Bully” is impressive, with excellent backgrounds, solid character animation and splendidly immediate action sequences. Unfortunately, in the flat-screen format, which is how most people will see it, the pictorial impact is substantially diminished and the film isn’t appreciably superior, either in content or appearance, to the regular run of Saturday-morning TV fare.

The verdict? If you see “The Ant Bully” in IMAX 3-D, the sheer visual extravagance may make up for its storytelling defects and acute lack of charm. Otherwise, you’ll reach for the insecticide well before the movie is over.