What substance, chemically similar to fat, is produced from nectar by bees and what is it used for?

The worker bee secretes wax from special wax glands on its abdomen, The honeycomb and broodcomb are constructed by the worker bees using this secretion. The comb consists of hollow wax cells each large enough to hold a small quantity of honey, pollen, or a developing worker or drone.

When the worker bee sucks up nectar from a flower it passes into a part of the bee's gut called the crop. Digestive enzymes, are secreted into the crop. In the hive the bee empties its crop into a cell.

Nectar is the carbohydrate supply for the hive. Placed in honeycomb cells it evaporates (loses much of its water content) as a result of the ventilation produced by worker bee rapid wing movements inside the hive. By the time a nectar filled cell is capped off by a worker bee it has become the concentrated sugar solution that we call honey.

Pollen collected on worker bees' legs as they forage for nectar is stored in broodcomb cells as the main supply of protein and vitamins for the hive.