Imitation may still be the sincerest form of flattery, but in children’s movies today repetition is apparently the key to success. “Continental Drift,” the fourth installment of the animated “Ice Age” franchise that started in 2002 and continued with “The Meltdown” in 2006 and “Dawn of the Dinosaurs” in 2009, offers little that isn’t familiar—unless I’m mistaken, some of the interpolations involving Scrat, the slapstick rodent, are actually recycled from previously-shown shorts. But even the certifiably “new” material feels lifted from other family pictures, or at least “inspired” by them, most notably a whole pirates subplot that comes across as all too predictable in the Jack Straw era (as well as inferior to the Aardman take in “Band of Misfits”). That’s frankly like the introduction of dinosaurs into the last installment (though to be fair, one of the few witty lines in “Drift” is a self-deprecatory throwaway about the historical inanity of that plot). The recycling motif extends even to the “Simpsons” short being shown before the feature. It’s easily the most enjoyable part of the entire ninety minutes, but “The Longest Daycare,” as it’s titled, revisits the Ayn Rand center for tots that was featured in an old episode of the TV show.

In any event, “Drift” begins with Scrat’s visit to the molten core of the earth in pursuit of his beloved acorn, which accidentally sets the planet’s land mass dividing into continents. Plodding mammoth Manny (Ray Romano), goofy sloth Sid (John Leguizamo) and sharp-tongued saber-toothed tiger Diego (Denis Leary) find themselves separated from everyone else, including Manny’s wife Ellie (Queen Latifah) and his teen daughter Peaches (Keke Palmer), whom Manny’s been hovering over like a helicopter dad. Their only companionship comes from Sid’s cantankerous old grandma (Wanda Sykes), whom his family dumped on him during a brief-as-possible drive-through.

Manny’s whole purpose is to get back to his family, but the effort brings the crew into conflict with a nasty orangutan pirate captain named Gutt (Peter Dinklage), who sails about on ice floes stealing stuff from anybody he encounters. His crew is pretty anonymous except for Shira (Jennifer Lopez), a silver saber-tooth tiger who, naturally, challenges Diego before they get romantically involved and she turns against Gutt. The apparently gaga granny also proves, in the last resort, essential to the success of Manny and friends not only in finding their old community but in helping rescue Ellie, Peaches and the rest from the chaos caused by the collapse of a land bridge (a circumstance curiously similar to the crisis central to “Happy Feet 2”).

“Continental Drift” is loaded with lessons. At the forefront, of course, is the importance of family—not just of the biological variety, but the family of friends and neighbors one helps and is helped by. Then there’s the learning curve between parents and children. Peaches learns that her dad isn’t just an old fogy but has her best interests at heart, and Manny learns that his daughter needs space. And that’s just the tip of the iceberg of instruction, if you’ll pardon the expression.

Of course the filmmakers’ aim is to make the morals go down easily, so they’re presented in a lighthearted fashion, with plenty of slapstick to please the tykes and lots of action in the form of chases to keep things moving. And interludes with Scrat are introduced periodically in an attempt to generate big laughs. But the humor is generally pretty limp; even the Scrat bits come across more and more as pale reflections of old Wile E. Coyote formula. And the action sequences grow repetitive over the long haul, with Gutt a rather boring character. Scanty attention is given to the more sophisticated jokes designed to appeal to adults while youngsters are otherwise engaged; sub-teen viewers won’t find much that might go over their heads here.

Still, the very young will probably be satisfied, and everyone can admire the computer-generated visuals, which cater to the 3D format in ways toddlers will certainly appreciate. They’re bolstered by John Powell’s score, though the misuse of themes from Beethoven (including the last movement of the Ninth Symphony) is unfortunate.

Most animated franchises—and live-action ones, too—have had the wisdom to shut down after three episodes. The real glacial era went on for a very long time, but the “Ice Age” franchise really needn’t try to match its longevity. Enough, already.