Peeping at the sun in the morning (4,6)
I believe the answer is:
dawn chorus
'peeping at the sun in the morning' is the definition.
I can't tell whether this definition defines the answer.
'at the sun in the morning' is the wordplay.
'at' is a charade indicator (letters next to each other).
'the sun in' becomes 'chorus' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'the morning' becomes 'dawn' (synonyms).
'chorus' put after 'dawn' is 'DAWN CHORUS'.
Can you help me to learn more?
(Other definitions for dawn chorus that I've seen before include "Early morning sing-song?" , "Bird song at daybreak" , "Birdsong" , "singing, naturally" , "Early sound of birds" .)