Nuts they may be, but they're in charge! (5)
I believe the answer is:
heads
'nuts' is the definition.
The definition and answer can be both man-made objects as well as being plural nouns.
Perhaps they are linked in a way I don't understand?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for heads that I've seen before include "Goes for" , "a 50-50 chance" , "Coin-tossing call" , "School principals" , "Noddles; nuts" .)