  In this note we consider whether there could be Swampland constraints
associated to the presence of fermions in the theory. We propose that any
fermion must couple to an infinite tower of states, and that the mass scale of
this tower, in Planck units, is set by the strength of the Yukawa coupling to
the tower. This is a type of fermionic version of the (magnetic) Weak Gravity
Conjecture. We also find that supersymmetry plays a natural part in this
fermionic realisation, which motivates a further proposal that supersymmetry
can only be broken below the scale set by this Yukawa coupling. We perform some
preliminary checks in string theory of these ideas.
