An adapter (10) is disclosed for a human stereotactic device to adapt the human stereotactic device for use with an animal. An adapter (10) comprises at least one skull attachment feature (14) for attaching the adapter to the skull of an animal, and at least one device attachment feature (16) for attaching the adapter (10) to the human stereotactic device. The at least one device attachment feature (14) is or are substantially the same as or equivalent to or compatible with at least one attachment feature provided on a base ring or base ring platform for the human stereotactic device for attaching the base ring or base ring platform to the human stereotactic device. This allows the human stereotactic device to attach to the adapter without modification of the human stereotactic device.
