Bees in winter - bees don't hibernate, they cluster in the hive to keep warm (The melted snow in the middle of the roof shows that all is well with these hives)
Wire mesh keeps woodpeckers off in the winter
Bees in spring - the queen starts to lay more eggs and the colonies increase in size rapidly. Bees will fly whenever the weather is warm enough - about 16C to forage
Left unchecked colonies will swarm in May or June. This is their natural way of increasing the number of colonies. The queen lays eggs to create new queens in the old colony and then leaves with a large number of mature bees. They will cluster somewhere while scouts look for a suitable new home.
If you see swarming bees please call a beekeeper a soon as you can - local swarm collectors can be found vis the British Beekeeping website - www.bbka.org.uk
