Mosquito. Coloured environmental scanning electron micrograph (ESEM) of a mosquito (family Culicidae). Large compound eyes (blue) are seen on the mosquito's head. Two antennae are seen mounted near the eyes (curving away to either side of the head). The three mouthpart structures are seen: two hairy palps (curving up to upper left); and a long straight proboscis (extending downwards and left). This is used by a female mosquito to pierce the skin of a mammal (such as a human) and feed on its blood. The other structures seen are the legs, thorax (centre right) and wings (across top). Several mosquito species transmit human diseases such as malaria and yellow fever.