Patent ID: 7874267

Claim:
An airtight animal breeding unit comprising: an airtight external tray; an internal tray; a mesh cover; and an airtight lid; wherein the external tray comprises a bottom, side walls, and an upper opening, an inner surface of each of the walls being formed to have a first stepped portion along an entire perimeter of the external tray and that is parallel to the bottom, and a brim surface is formed along an outer perimeter of the upper opening; wherein the internal tray is the same shape as the external tray and is configured to fit wholly within the external tray such that when the internal tray is disposed wholly within the external tray the internal tray is supported by the first stepped portion of the external tray and constructed so that an animal contained within the internal tray cannot contact the external tray, the internal tray configured to be disposable and comprising sufficient space for breeding an animal of interest, wherein walls of the internal tray are formed to have a second stepped portion configured to occupy the external tray first stepped portion around substantially an entire outer boundary of the internal tray, the internal tray including an upwardly-extending brim portion that extends above side walls of the internal tray; and wherein the lid is directly attachable to and detachable from the brim surface of the external tray; wherein contacting surfaces of the lid and the brim surface are formed to maintain airtightness when the lid is attached to the brim surface of the external tray; wherein the lid includes at least one opening configured for airtight connection to an environment-maintaining device; and wherein the mesh cover is configured for preventing an animal from escaping, the mesh cover being supported by the second stepped portion of the walls of the internal tray.