Bumble bee head, coloured scanning electron micrograph (SEM). This is the head of a bumblebee. Bumblebees have two sets of eyes. The two large compound eyes (left and right) are combined with dorsal ocelli or 'simple eyes' on top of the head. The ocelli are thought to aid stability during flight as well as monitoring light levels. The antennae (sensory structures) are the stalk-like structures between the compound eyes. Magnification: x10 when printed at 10 centimetres across.