Herewith I describe the chickenly ritual known as The Laying of the Sun.
This ceremony occurs between first light and full light on days determined by a complex, possibly lunar-influenced, ritual calendar. It is most frequently observed just before the summer solstice, though occasional celebration occurs all year, or at least the parts of the year in which (a) I am awake already when the sun comes up or (b) we've left the bedroom window open.
During the ritual, one chicken (usually Norska, I think, although they're hard to tell apart by voice) takes the role of Mother of the Sun and re-enacts the original laying of the sun, with fanfare and song. Note that this re-enactment does not include the production of an actual egg; egg production happens much later in the day and is typically accompanied by much less fanfare and very little song. The troubles and strife experienced by the Mother of the Sun are described in lurid and exacting detail by this High Priestess, supported at intervals by a full chorus of all the other chickens. The song then shifts into a profound and celebratory triumphal march, again supported at intervals by a full chorus of all the other chickens. Possibly they are re-enacting a Narnian sort of singing the world into existence; the song's division into clear individual segments tends to support a narrative interpretation.
Once the ritual is complete, the chickens go about the usual business of the morning. The ceremony does not appear to be accompanied by any fasting or particular ceremonial foodstuffs, nor by any complex personal preparations or alterations to the ritual space.
There are, however, occasional rehearsals.
 As described in Lewis, C.S. (1955). The Magician's Nephew. London, England: The Bodley Head.