Little mischief-makers, half of Devon's swimmers (8)

I believe the answer is:

devlings

'little mischief-makers' is the definition.
(a devling is a young devil)

'half of devon's swimmers' is the wordplay.
'half of' indicates taking half.
'swimmers' becomes 'lings' (type of fish, something that swims).
'devons' with half the letters taken is 'dev'.
'dev'+'lings'='DEVLINGS'

I've seen this clue in The Guardian.

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