Crowd on move in endless war mayhem (5)

I believe the answer is:

swarm

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'crowd on move' is the definition.
'swarm' can be an answer for 'crowd' (swarm is a kind of crowd). I'm unsure of the 'on move' bit.

'in endless war mayhem' is the wordplay.
'in' indicates the answer is hidden within the clue.
'SWARM' is hidden in the letters of 'endless war mayhem'.

Can you help me to learn more?

(Other definitions for swarm that I've seen before include "Climb; cluster of bees" , "Flight of bees" , "Body of bees" , "Dense cloud (of insects)" , "Host" .)

I've seen this clue in The Sun.

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