The bird did fly inside to get under cover (6)
I believe the answer is:
'under cover' is the definition.
'the bird did fly inside' is the wordplay.
'the bird' becomes 'hen' (hen is a kind of bird).
'fly' indicates an anagram.
'inside' is an insertion indicator.
'did' with letters rearranged gives 'idd'.
'hen' going around 'idd' is 'HIDDEN'.
'to get' acts as a link.
(Other definitions for hidden that I've seen before include "not obvious" , "behind closed doors" , "Deliberately placed out of sight and hard to find" , "Abstruse" , "Concealed, placed out of sight" .)