It is the belief of Hindus that ancestors are to be respected and one should express gratitude to them because of them we are what we are .This respect is to be offered with complete Faith, though the Sanskrit word Sraddha’ s full import is not expressed in the term Faith. In this context, Sraddha’ means, in addition to Faith, dedication and an attitude of reverence to ancestors.This offering of Sraddha is to be performed daily; it got diluted to 96 and now it is once a year!Please read my articles on Sraddha for details.
After the Sraddha ceremony is over at home, food prepared is first offered to Crows. Only then can the Priests and householders partake food.
The offering of food to Crows , is not limited to Sraddha days. Food has to be offered to Crows daily. Food has to be offered to Deities daily. Freshly cooked food is to be offered. There are different views on whether one can offer the food offered to Deities, Naivedya, can be offered to Crows as Crows represent Pitrus.My view is that Same food may be offered to Deities and Crows separately and not the food offered to God to pitrus or the other way around.
Concept of Pitrus, I have written in detail. I am providing Mantra to be recited while offering food to Crows. This was difficult to come by. I expressed this in one of my articles. Sri. Vasudevan has taken the trouble of searching for the Mantra and forwarded it to me. Thanks Sri.Vasudevan.