The worms, according to Mike Johns, set up intestinal and liver problems and lower the immunity of the bird , so that secondary problems arise and the bird cannot digest food.
The bees build up a store of honey during the summer which they eat through the winter. Beekeepers will take a surplus of honey from the hive, but won't take all the honey there is. They also feed the bees with sugar syrup after taking the honey to make sure the bees have enough to see them through the winter. Honey.
Some beekeepers will also ensure they keep plenty of the bees' own honey in store during the winter, in case the bees need it. (Note, it is important that honey bees are only fed their own honey, to ensure viruses and disease do not spread between different bee colonies).