  In the light of the recent analogs of the Hanbury--Brown and Twiss
experiments in mesoscopic beam splitters, negative current noise correlations
are recalled to be the consequence of an exclusion principle. Here, positive
(bosonic) correlations are shown to exist in a fermionic system, composed of a
superconductor connected to two normal reservoirs. In the Andreev regime, the
correlations can either be positive or negative depending on the reflection
coefficient of the beam splitter. For biases beyond the gap, the transmission
of quasiparticles favors fermionic correlations. The presence of disorder
enhances positive noise correlations. Potential experimental applications are
discussed.
