From "Cast Away" to "American Beauty" to "Saturday Night Fever," the "Madagascar" series contains a ton of movie references that adults will enjoy. But since almost all of them are nods to older movies and movies that aren't for kids, they will likely go right over children's heads.
Nonetheless, some of these bits are still funny whether you notice the movie reference or not. For example, the first film includes a reference to "Planet of the Apes." As Alex's replica of the Statue of Liberty burns to the ground, leaving only part of its upper body poking out of the sand, Alex yells, "You maniac!" in response. While the reference to Charlton Heston's devastating discovery at the end of the 1968 movie makes for a funny moment, kids who've never even heard of "Planet of the Apes" are likely to laugh right along at Alex's exaggerated response.
Similarly, early in the second movie, when Alex looks out the window of the animals' plane, he sees Mort on the wing and initially mistakes the small lemur for a gremlin. While adults of a certain age will have no trouble recognizing this as a reference to "The Twilight Zone," the scene is still comical enough to elicit a few chuckles whether viewers understand the nod to the classic series or not.