Night at the Museum rarely is entertaining, but it’s at least instructive. The statute of limitations on loud, dumb movies with Robin Williams and computer-generated animals is 11 years.

And if you’re wondering where Ben Stiller has been for most of the last two years, he’s been peed on by a monkey and verbally abused by Mickey Rooney in a toothless effects-reel comedy.

Museum is an uninventive cross between Jumanji, Bill & Ted’s Excellent Adventure and the sort of fractured-family sap in which producer Chris Columbus once specialized. It already feels like the straight-to-DVD sequel without prestigious brand-name coattails on which to ride.

Stiller plays Greg, uh, Reuben, uh, Ted, I mean, Larry, a divorced, devoted dad with dead-end job opportunities. Virtual-reality golf and “The Snapper” (like the Clapper, but with snapped fingers) are invention ideas that have gotten him nowhere. He feels destined for greatness, but his son (Jake Cherry) asks him, “What if you’re just an ordinary guy who should get a job?”

Thinking it’s an instructional position at New York’s Museum of Natural History (which his poor history knowledge would discredit anyway), Larry accepts a temp listing, only to find he’s the new night watchman. Larry is a downsizing replacement for Gus, Cecil and Reginald (Rooney, Dick Van Dyke and Bill Cobbs), the elderly workers currently keeping guard.

What they neglect to tell Larry in a training session is that, at night, everything in the museum comes to life — mischievous monkeys, dinosaur bones, homicidal Huns, Sacagawea, Williams as Teddy Roosevelt, miniature Mayans slightly less violent than those in Apocalypto. Either they run wild, lope like early-morning mall walkers or, in Williams’ case, assist Larry with self-confidence.

Any semblance of real plot comes with only 20 minutes remaining, and a ploy to pilfer the museum. The actors in the movie should have worried about sneaking out of their contracts.

Stiller is stuck as the worst sort of straight man, one saddled with visual effects and animals. In cameos, Owen Wilson and Steve Coogan make you marvel at what a fine pair they’d be in a movie that bothered to be good. It’s the second American movie to waste the great British comedian Ricky Gervais. And a temperamental Rooney barks out food-related nicknames like “snack shack” and “lunchbox” at Stiller. It’s still a step up from washing non-existent dishes in insurance commercials.

Most museums take all day to explore, but this one just feels that way. Still, like most tourist attractions, it has highlights: one killer Stiller ad-lib about the Civil War; a great perspective gag with Wilson and Coogan; and a physical blow from Rooney is the only thing to draw Stiller’s blood with all his injuries. Other than that, the exhibitions in this Museum just aren’t worth the time.