Dear all,
What an imaginative collection of "collective nouns"!
There are many accolades to be awarded: tom, John, Andrew, linmag, Byron, partisan, witty-owl, Pete, to mention a few.
Mazeltov, but can return to my "homework" question....."a murder of crows"?
I've thought long and hard about this one: after all, it would be nice to win the prize in the competition I'd devised in the first place

.
There is a reference to crows in Shakespeare's "MacBeth", as Duncan's soldiers are advancing. Lady MacBeth makes the remark .
The other possibility is the Scots ballad "The Twa Corbies", about which I'll say more later.
Andrew.