As Rik already pointed out, the ant is not a worker because the worker morph of ants does not possess wings and the typical mesosoma to support the wings and their muscles one recognizes on the photo. Though the end tip of the gaster isn´t shown, some other morphological traits that can be seen indicate that it isn´t a typical male. It is most probably a young queen since normally males die shortly after the nuptial flight without having shed their wings.
So most probably this young queen has ended her nuptial flight not long ago, is in the process of wing-shedding and further trying to pass her genes to a new generation one day, depending on the species that means to found a new colony or to join an existing colony in one or another way (Note, there are several different ways in such a large and diverse taxon as the ants).
Interestingly, on Ken´s photo it looks as if the young queen is holding something in her mandibles.
Now, this behaviour provides matter for speculation:
It could mean that she is foraging and that it is a food item. Young queens do that, e.g. when they found a new colony in a mode that is called semiclaustral.
But there could be another possible and yet more absorbing, though highly speculative way of explanation: As you know, quite a lot of ant species are tending plant sucking insects in a mutualistic relationship. A young queen of such a species that is founding a new colony faces the problem of providing with new such "cattle".
In fact it has been reported repeatedly that young queens of some ant species carry a specimen of the insects used as cattle with them on the nuptial flight . (One could compare this to a farmer´s daughter who takes a cow as dowry with her. Most fascinating, isn´t it!?).
So the queen on the photo might carry such a plant sucking insect but as one can´t identify what species/genus of ant it is and what she is actually carrying I wanna stress again that this explanation is highly speculative but hopefully provided you with some intriguing facts of ant biology at least.
Best wishes,
Betty