I rarely use common names when talking about ants with fellow scientists & naturalists. I don’t see the point in vague and shifting terms when everyone in the room understands the precise taxonomic names. Rather, that I include common names in some posts is a matter of audience.
Consider the following search term data from the Google Keyword tool:
People who are most likely to need a guide to urban ants (hint: they aren’t professional myrmecologists) are liable to arrive at my post via search, and they aren’t going to be searching with the Latin names. Common names are strictly a practical matter here.