The AnimalGate is a fundamental extension to IntelliCage that permits selective passage of mice to a variety of external arenas or experimental set-ups. The AnimalGate uses the same transponder technology as IntelliCage and is controlled by the upgraded IntelliCage Plus software. It represents the vital controlled connecting structure of a future multifunctional modular test system. One or several AnimalGates can be added to each IntelliCage allowing selective access to different arenas such as ActivityBox, FeederBox, or others. Any basic IntelliCage system can be expanded gradually to the maximal setup.