  I use a combination of state-of-the-art numerical simulations and analytic
modelling to discuss the scaling properties of cosmic defect networks,
including superstrings. Particular attention is given to the role of extra
degrees of freedom in the evolution of these networks. Compared to the 'plain
vanilla' case of Goto-Nambu strings, three such extensions play important but
distinct roles in the network dynamics: the presence of charges/currents on the
string worldsheet, the existence of junctions, and the possibility of a
hierarchy of string tensions. I also comment on insights gained from studying
simpler defect networks, including Goto-Nambu strings themselves, domain walls
and semilocal strings.
