Intimations of the Divine are communicated through Pitrus.

Vayasamu is a significator of Pitrus. Another name for Vayasamu in Sanskrit is Kakaha. The actual meaning of the word Ka is Brahman. They are representatives of the Brahman. They are the messengers between us and the Brahmaloka. The people who are in the higher plane, who may be reborn, to them the messages are carried. Pindam is kept for such people only. The Kakahas go and give it them. If you pass this stage, then there is no chance of keeping Pindam. So, at this level, the Vayasamu only can go. Messengers means, when a good thing happens or a bad thing is to happen, it is the domestic crow that forewarns. The domestic crow, in Hindu religion is equated with the Pitrus.

In the 'Book of Signs', you will find the crow. Basically you get to know what it is. After that level there is no chance of communicating, they only have to take the message. That is why offering vayasamu is a must for anybody, everyday. It is not something that is kept only on shraadha days.

Vayasamu is a link between the pind desh and the brahmand.