For gods like Ganesha, Shiva, Vishnu and many others, the idol of the Vahana (animal or otherwise) is placed outside the garbagriha (the innermost sanctum of a Hindu temple) in most temples.
Yet in many references to vahanas in holy texts, they are supposed to be be always present alongside God(s). Why is this?
The garbha griha represents the innermost sanctum of the deity's loka. Here only the deity and their consort(s) reside. When the garbha griha doors close, their Lordships finally have some privacy, and this is when they sleep. The vahana, the Lordship's greatest devotee, is always eager to serve, and waits just outside the sanctum, in line-of-sight of the Lord.
