They make eye contact and draw attention to themselves, but it is
up to the male to make the approach and say the first word.
This author--Friar Wall of The
Monastery distinguishes between passivity and "proceptivity",
which is described as common female flirting behavior.; there may also be
useful discussion at this
site, but I can't verify that, as I have been unsuccessful connecting
to it so far.
Desmond Morris gives his summary here.