Experimentally, baryon number minus lepton number, B-L, appears to be a good global symmetry of nature. We explore the consequences of the existence of gauge-singlet scalar fields charged under B-L-dubbed lepton-number-charged scalars (LeNCSs) - and postulate that these couple to the standard model degrees of freedom in such a way that B-L is conserved even at the nonrenormalizable level. In this framework, neutrinos are Dirac fermions. Including only the lowest mass-dimension effective operators, some of the LeNCSs couple predominantly to neutrinos and may be produced in terrestrial neutrino experiments. We examine several existing constraints from particle physics, astrophysics, and cosmology to the existence of a LeNCS carrying B-L charg...