She was looking for a nesting site. This prowling gait and checking behavior are typical for foundresses of ground-nesting species. Bad omen for the players, but good example of an extensively yellow specimen.
If this can reassure you a bit, less than one female of every nearly 500 will manage to start a colony. Moreover, many foundresses in spring does not mean many nests in late summer: ironically, things can even go the other way.