A disposable animal cage which can be used in a ventilated or static caging rack system includes a cage top and a cage base. Any corner or edge present in the interior of the cage base or the cage top that is accessible to an animal that can be contained in the cage is defined by surfaces having a conical section which is non-circular to prevent gnawing of the cage. A perforation section including a plurality of small apertures adjacent to one another can be formed in the cage for ventilation and prevention of gnawing by the animals.