The Latvian animated film is a wordless survival story that lets its animals act like animals. Photo: Janus Films There are no people in Flow , an animated movie from Latvia about the adventures of a black cat, a yellow Lab, an unflappable capybara, a tetchy lemur, and an aloof secretary bird that band together to survive a cataclysmic flood. But traces of humanity are all over its drowned landscape, offering contradictory clues about what might have led to our absence. The house that the movie’