A worker bee is any female (eusocial) bee that lacks the full reproductive capacity of the colony's queen bee; under most circumstances, this is correlated to an increase in certain non-reproductive activities relative to a queen. While worker bees occur in all eusocial bee species, the term is rarely used (outside of scientific literature) for any bees other than honey bees. Honey bee workers gather pollen into the pollen baskets on their back legs and carry it back to the hive where it is used as food for the developing brood. Pollen carried on their bodies may be carried to another flower where a small portion can rub off onto the pistil, resulting in cross pollination. A significant amount of the world's food supply, particularly fruit, depends greatly on crop pollination by honey bees. Nectar is sucked up through the proboscis, mixed with enzymes in the stomach, and carried back to the hive, where it is stored in wax cells and evaporated into honey. Life cycle Although the life span of a worker bee is longer than that of a drone, it is generally only a few months, and rarely can survive a year. The life span is 1-2 months in summer and can be up to 6-8 months over autumn and winter. The lifespan of summer worker bees can increase to 6 months if placed in a colony that doesn't have a queen. Honey bee workers keep the hive temperature uniform in the critical brood area (where new bees are raised). This is in the centre frames of the brood box. Workers must maintain the hive's brood chamber at 34.4 °C to incubate the eggs. If it is too hot, they collect water and deposit it around the hive, then fan air through with their wings causing cooling by evaporation. If it is too cold, they cluster together to generate body heat. This is an example of homeostasis. The life of all honey bees starts as an egg, which is laid by the queen in the bottom of a wax cell in the brood area of a hive. A worker egg hatches after three days into a larva. Nurse bees feed it royal jelly at first, then pollen and honey for six days. It then becomes an inactive pupa. During its 14 days as a pupa, sealed in a capped cell, it grows into a worker (female) bee, emerging