They’re foolish to do it, anyhow, when one’s around (6)
I believe the answer is:
idiots
'they're foolish' is the definition.
The definition suggests an adverb but the answer is not.
'do it anyhow when one's around' is the wordplay.
'anyhow' indicates an anagram.
'when one' becomes 'is' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'around' is an insertion indicator.
'do'+'it'='doit'
'doit' with letters rearranged gives 'diot'.
'diot' going inside 'is' is 'IDIOTS'.
'to' is the link.
Can you help me to learn more?
(Other definitions for idiots that I've seen before include "clowns?" , "imbeciles" , "Foolish ones" , "Foolish people" , "Abusive word for unintelligent or irrational people" .)