This bird will always turn up for some millet (6)
I believe the answer is:
pullet
'this bird will always' is the definition.
'pullet' can be an answer for 'bird' (pullet is a kind of bird). I am not sure about the rest of the definition.
'turn up for some millet' is the wordplay.
'turn' says the letters should be written in reverse.
'for' says to put letters next to each other (I've seen this in other clues).
'some millet' becomes 'tell' (I can't explain this - if you can you should give a lot more credence to this answer).
'up' put after 'tell' is 'tellup'.
'tellup' reversed gives 'PULLET'.
Can you help me to learn more?
(Other definitions for pullet that I've seen before include "No high-flyer" , "A young domestic hen less than one year old" , "Young domestic fowl" , "Chicken under one year old" , "Young chicken" .)