Ravens have the unusual distinction of having different collective nouns depending on what the group is doing. A group of ravens or rooks feeding or hunting together is an unkindness, but a group of them watching something together is a constable of ravens. If they are chatting or conferring together they are either a conspiracy or a parliament of ravens… note that any group of owls is always called a parliament, which seems odd given owls’ (somewhat undeserved) reputation for wisdom and the notable lack thereof in most parliaments.
Like magpies and crows, ravens have a traditional rhyme.
One for bad news,
Two for mirth.
Three is a wedding,
Four is a birth.
Five is for riches,
Six is a thief.
Seven, a journey,
Eight is for grief.
Nine is a secret,
Ten is for sorrow.
Eleven is for love,
Twelve, joy for tomorrow.
Corvids are believed to be the most intelligent of birds, and the raven (Corvus Corax) is the most intelligent bird that has been tested to date.
Or to put it in a more traditional way: Tha gliocas an ceann an fhitich – “There is wisdom in the head of the raven.” You can see it in the whites of their eyes.