Ah yes, it keeps coming back to the basics of survival - food and shelter being at the top of the list. We do have some info on Zeds eating things other than people (even regular ole food). So I wonder if humans as the food source is the main driving factor in Zed-land right now.
We saw an evolution of behavior amongst our human friends in WA from "get somewhere safe" to "get something to eat" to "we might have to be here a while" in terms of what their objectives/actions were. If you subscribe to the theory that the Zeds are (at least in some individuals) still partly human or hold onto some human intelligence/rationalization, then we could see this convergence on
the Colony as the Zed equivalent of survival behavior.
And, for all we know at the moment, we could have 2 (or more) Zed factions in LA just like we had human groups.
Randy's group could be an equivalent to
the Tower folks and TOWTM's group could be like
the Mallers.
I'm just throwin' it out there....