Ocelli, in the context of a honeybee (Apis mellifera), are simple eyes located on the top of the bee’s head. They are distinct from the compound eyes, which are larger and more prominent. Honeybees have three ocelli arranged triangularly between their two large compound eyes.
Ocelli are smaller and have fewer facets than compound eyes, consisting of thousands of individual lenses. They are usually black or dark in colour and have a smooth appearance. Unlike compound eyes, ocelli do not provide detailed images or form complex visual perceptions. Instead, they serve specific functions related to flight and navigation.
The primary role of ocelli in honeybees is to detect changes in light intensity, particularly polarised light patterns. This ability is essential for the bee’s orientation and navigation during flight. Ocelli are sensitive to changes in light direction, helping the bee maintain stability and adjust its flight path based on the sun’s position or other light sources in the sky.
While ocelli play a crucial role in honeybee flight, most visual processing and complex vision tasks are carried out by the compound eyes, allowing bees to see a wide range of colours, shapes, and patterns in their environment.