Animals walk around (4)
I believe the answer is:
pets
'animals' is the definition.
(pet is a kind of animal)
'walk around' is the wordplay.
'walk' becomes 'step' (I've seen this before).
'around' is a reversal indicator.
'step' back-to-front is 'PETS'.
(Other definitions for pets that I've seen before include "Animals at home" , "Little darlings - step on them" , "Domesticated animals" , "Domestic animals" .)