Nine-banded armadillos (Dasypus novemcinctus) have a typical mass density of 1200 kg/m³ and a mass of 7.0 kg (including their armor). When faced with a body of water to cross, the armadillo has two choices: to hold its breath and walk across the bottom or to swallow air into the stomach and intestine and float across. Approximately what volume of air does it need to swallow in order to float? Assume the swallowed air is at atmospheric pressure.