I called to help a beekeeper last week that has one hive. On inspection she had found the colony to be apparently queenless.
However we, or rather she found the queen, that was the first time that she had seen her. As there was a fair number of worker bees present it was decided to offer them a frame of brood and larvae. Maybe they would draw a queen cell or two to supersede or the presence of the emerging brood would stimulate the queen into lay?
I had suggested that the colony was a lost cause, the queen should be culled and the rest united with a nuc.
I returned today with said frame. As soon as the crown board was lifted the bees were on me: sting to my wrist in 5 seconds!
The lesson here: Don’t let the bees hear your plans, they don’t forget!
See here why you should ideally keep more than one hive: https://woodsideapiary.blogspot.com/2020/01/how-many-bee-hives-should-you-have.html