Write "The animal is hiding in the trees" (6)
I believe the answer is:
aspens
'trees' is the definition.
(aspen is a kind of tree)
'write the animal is hiding' is the wordplay.
I cannot really see how this works, but
'write' could be 'pen' (synonyms) and 'pen' is found within the answer.
'animal' could be 'ass' (term for a donkey) and 'ass' is found within the remaining letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'in the' is the link.
Can you help me to learn more?
(Other definitions for aspens that I've seen before include "Quivering poplars" , "Kind of poplars with shivering leaves" , "Poplar trees that shiver in the wind" , "Trees with leaves that quiver" , "Species of poplars with leaves that quiver" .)