  We study the prospects of pinning down the effects of non-standard
antineutrino interactions in the source and in the detector at the Daya Bay
neutrino facility. It is well known that if the non-standard interactions in
the detection process are of the same type as those in the production, their
net effect can be subsumed into a mere shift in the measured value of the
leptonic mixing angle theta_13. Relaxing this assumption, the ratio of the
antineutrino spectra measured by the Daya Bay far and near detectors is
distorted in a characteristic way, and good fits based on the standard
oscillation hypothesis are no longer viable. We show that, under certain
conditions, three years of Daya Bay running can be sufficient to provide a
clear hint of non-standard neutrino physics.
