The four named guardian scarabs will not become attackable until you walk onto the raised circular area in the central area. Once all four are killed, Queen Ankhestara will spawn.
The lockout starts as soon as one of the named guardian scarabs is killed.
Layout[]
The hive is laid out like a cross with the entry door in the south wing. The west, north, and east wings are recessed pit areas with stairs down into them. The central area has a slightly raised circular area.