Most newbies think there is only one laying worker that has replaced the queen and do not realize that laying workers exist in a queen right hive.
The subject of Laying Workers seems to be yet another debatable area of beekeeping. There appears to be two competing views: some authorities suggest that LW exist at all times, and that workers remove their eggs. The other view is that LW will not exist until the colony becomes queenless (and thus brood-less), as the development of their ovaries is suppressed until that time.
For a short while now I've been using a Joseph Clemens Queenless Hive, a system which relies on a colony maintaining a continuously Queenless status, and thus completely free of any Laying Workers - the presence of which would sabotage that Queenless status just as any genuine Queen would. Using this system requires that open brood be regularly introduced in order to prevent the development of Laying Workers, and thus supports the view that LW won't exist as long as open brood (emitting Brood Pheromone) is present.