I think everyone has fantasies about what our animals do when we're not around. Do they sit and stare at the door all day, waiting for our return? Do they watch soap operas? Do they invite friends over for wild parties? That's the central conceit of The Secret Life of Pets, the latest animated comedy from Illumination, the studio behind Minions and the Despicable Me films.

The hero of the story is Max (Louis C.K.), a Jack Russell-looking mutt owned by Katie (Ellie Kemper). She and Max live in an apartment in Manhattan, and have a close bond — so close that when Katie leaves every day for work, Max spends most of the day staring at the door, wondering when she'll be back.

Occasionally, other pets from the building will stop by, like Mel (Bobby Moynihan), a pug with a bit of ADHD; Chloe (Lake Bell), a fat and disinterested cat; and Gidget (Jenny Slate), a fluffy white lap dog with a mad crush on Max.

But one night Katie brings home Duke (Eric Stonestreet), a huge dog that resembles a cross between Snuffaluffagus and a Newfoundland. As can be expected, the two dogs don't get along. Their rivalry, through a series of conveniently bad events, results in them lost, collarless, and at the mercy of a gang of sewer-dwelling animal renegades intent on destroying humankind.

Kevin Hart's performance as rebel leader Snowball, an adorable-looking but militant rabbit, is a definite highlight in a movie that, from the main "what they do when we're not there" premise through to the central "rivals must team up to get back home" story, is a basic retread of Toy Story. Jenny Slate, who's already demonstrated she's got the perfect voice for animation with her series of Marcel the Shell shorts, also has a lot of fun with a character that starts out as a cliche, but turns into a fierce hero.

But Louis C.K. and Eric Stonestreet's voices are just a little too similar, and both Max and Duke are a little too dull to center a movie on. For the most part that's fine, since there are so many supporting characters to turn one's attention to (there's also Albert Brooks as a cranky red-tailed hawk, and Dana Carvey as an old, streetwise basset hound).

The stretches that just feature Max and Duke are a snore, and the film's attempts to wrestle some tears out of the story don't work. The character design is also kind of ugly and flat, as tends to be the case with Illumination's movies (after all, their biggest hits feature characters that basically look like identical yellow sleeping pills). The Secret Life of Pets is probably fast-paced enough to keep the kids engaged, but I say hold out for the inevitable Snowball-centered spinoff.