  The behaviour of the topological susceptibility in QCD with two colours and 8
flavours of quarks is studied at nonzero temperature on the lattice across the
finite density transition. It is shown that its signal drops at a
(pseudo-)critical chemical potential mu_c. The Polyakov loop and the chiral
condensate undergo their transitions at the same value. Pauli blocking
supervenes at a value of the chemical potential larger than mu_c.
