Re: Swarm left hive then flew back to hive 10 minutes later?
That sounds as if it were either a Pre-Swarm (queen gets oriented and house bees do too) or possibly a mating flight of a new queen. In two weeks they could have superseded the old queen and normally when she leaves the hive they will (swarm out) to help her get out of the hive safely on her way. Keep an eye open this may happen again in a day or two. If it does it's mating swarm, if not they will end up on a branch someplace instead.
Thomas Bartram - Since 2013, 43 - 8 F langs, 22 Italian & 21 Russian