  Diffusion is a fundamental aspect of transport processes in biological
systems, and thus, in the development of life itself. And yet, the diffusive
dynamics of active fluids with directed rotation, known as chiral fluids, has
not been analyzed in detail so far. Here, we describe the diffusive regimes of
a two-dimensional chiral fluid, composed in this case of a set of identical
disk-shaped rotors. We found strong experimental evidence of odd diffusion.
This odd diffusion emerges in the form of a two-dimensional tensor with an
antisymmetric part. In particular, we show that chiral diffusion is complex,
featuring transitions between super, quasi-normal, and sub diffusion, and very
slowly aging. Moreover, we show that the diffusion tensor elements, including
off-diagonal elements; i.e., odd diffusion coefficient, change sign according
to flow vorticity. Therefore, the chiral fluid has a self regulated diffusion,
controlled by its vorticity.
