  We characterize the $L^2$ decay rate of solutions to the 3D
magneto-micropolar system in terms of the decay character of the initial datum.
Due to a linear damping term, the micro-rotational field has a faster decay
rate. We also address the asymptotic behaviour of solutions by comparing them
to solutions to the linear part. As a result of the linear damping, the
difference between the micro-rotational field and its linear part also decays
faster. As part of the proofs of these results, we prove estimates for the
derivatives of solutions which might be of independent interest.
