The most common and most likely answer to this crossword clue is the 6 letter word GLOATS
I've seen this crossword clue in The Daily Telegraph
G
L
O
A
T
S
Buddy explains!

The straight part
We know that "Crows" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case crows = gloats.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does GLOATS mean?
GLOATS noun- An act or instance of gloating.
- To exhibit a conspicuous (sometimes malevolent) pleasure or sense of self-satisfaction, often at an adversary's misfortune.
- To triumph, crow, relish, glory, revel.