A base chassis supports a set of storage cages. The base chassis includes a front portion that is removably attachable to a first storage cage. The base chassis also includes an extension portion. The extension portion has a first end that is fixedly attachable to the front portion to extend a length of the base chassis to support an additional storage cage when the first storage cage is detached from the front portion. The extension portion also has a second end that is attachable to the first storage cage to support the first storage cage.