They are in a semi dormant state and cluster together to keep warm.
Yes, in the winter when it is too cold for them to leave their hive.
No,bees do it in autumn.
Bees within one hive can communicate with bees from another hive through scent trails, which they use to signal the location of food sources or new hive locations. This communication enables bees to share information and resources with bees from different hives within the same colony.
Bees
During winter, honey bees form a cluster inside the hive to keep warm. They vibrate their wing muscles to generate heat and protect the queen at the center. They rely on stored honey and pollen for food during the winter when there are fewer flowers available.
Where bees bring pollen is called a "hive." The hive is their home and the place where they store pollen, honey, and raise their young bees.
A bee hive is an artificial home for bees which has been provided by a beekeeper to keep his bees in. In prolonged freezing conditions, bees might find it hard to survive if their hive was unprotected. However, in an average North European winter, bees will survive perfectly well within their hive provided that they are sheltered from cold winds and damp within the hive. They cluster together to keep warm, and the bees are always changing position so that the same bees aren't always on the outside of the cluster.
A hive is a home in which bees are kept.
A queen honeybee lives a protected and 'easy' life. She can live three to four years! But drones or worker bees have an average lifespan of a few weeks (1 month) to months (about 6 months). Worker bees can get evicted from the hive! Without the hive and its protection, the evicted bees will die.
Honey bees do not hibernate. In cold weather they will cluster together in the hive and vibrate their wing muscles in order to generate heat. The temperature in the centre of the cluster will be in the order of 35 to 40 degrees Celsius, and bees on the outside of the cluster will move in as they cool off. Provided there are enough bees to maintain the required temperature and there is not too much heat loss through the hive wall, the outside of the hive can be completely frozen and the bees will be unaffected.
A bee hive isn't hexagonal. The cells that bees make from wax inside a bee hive are hexagonal and the bees use these cells to raise young bees and to store honey and pollen.
The noun 'hive' is a collective noun for a hive of bees and a hive of oysters.