  A plausible explanation for the existence of additional light sterile
neutrinos is that they correspond to modulini, fermionic partners of moduli,
which propagate in new large dimensions. We discuss the phenomenological
implications of such states and show that solar neutrino oscillation is well
described by small angle MSW oscillation to the tower of Kaluza Klein states
associated with the modulini. In the optimal case the recoil electron energy
spectrum agrees precisely with the measured one, in contrast to the single
sterile neutrino case which is disfavoured. We also consider how all
oscillation phenomena can be explained in a model including bulk neutrino
states. In particular, we show that a naturally maximal mixing for atmospheric
neutrinos can be easily obtained.
