An animal monitoring device and method comprising an animal cage and associated electronics slab is described. The device is suitable for use in a modular vivarium implemented in one or two racks adjacent to walls in a holding pod. There is a one-to-one relationship between fixed slabs and removable cages. A single camera provides range of functions: its field of view includes the entire area of the cage accessible to an animal it may observe water level in a water bottle it may observe food level in a food tray it may view activity on an exercise device it may read the rear of cage card. The shape of the food tray is specialized to meet these requirements. An inner-cage frame holds elements in fixed locations within the cage. The cage is free of electronic penetrations. Supply and return air for the cage passes through the slab.