Poles embracing it - they are fools (4)
I believe the answer is:
nits
'are fools' is the definition.
(I've seen this in other clues)
'poles embracing it' is the wordplay.
'poles' becomes 'ns' (north and south poles).
'embracing' is an insertion indicator.
'ns' going around 'it' is 'NITS'.
'they' is the link.
This may not be correct. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for nits that I've seen before include "Fools" , "Tins of parasitic insect eggs" , "Eggs; stupid people" , "Eggs of lice" , "Head lice" .)