You Melbourne people know what I am talking about and so do you Sydneysiders. Except we have a slightly different language. I recall being puzzled by a Sydney friend's reference to cockies and how he was killing them en masse. How cruel I thought and why would you kill such entertaining birds when he lived in concrete and not red cedar?
We in Melbourne know cockies as cockatoos, a bird, but filthy Sydneysiders know them as cockroaches, or roaches or cockies.
It has come to pass that we cross over. DB has cockies and R does at his work place too. R's invasion sound like they are of the native variety, not sure about DB's.