The dry humor in this seems to come mostly from its simplicity and straightforwardness. A bat tells its life story, complete with short, concise details that are still brutally real to it, but without the anxiety or neurosis we'd come to expect from a human being. Fellow bats die, sexual attraction is discovered, ultimate extinction is assured, and food is hunted for with the same matter-of-factness as breathing.
The "simple" animation style helps that effect, though I'd like to point out that a lot of it isn't quite as simple as it seems to be. Especially during the sexual intercourse scenes there is this layered effect created by seemingly absurd and confused lines, which causes the imagination and interpretation of the events to be a lot more open than what one would expect from what looks like someone just traced over and over.
--PolarisDiB
The "simple" animation style helps that effect, though I'd like to point out that a lot of it isn't quite as simple as it seems to be. Especially during the sexual intercourse scenes there is this layered effect created by seemingly absurd and confused lines, which causes the imagination and interpretation of the events to be a lot more open than what one would expect from what looks like someone just traced over and over.
--PolarisDiB
