Fly's tongue, coloured scanning electron micrograph (SEM). Flies do not have a muscular tongue like humans, but the tip of their proboscis has a similar sensory function. This is the labellum, one of a pair of pads on the proboscis' tip that is responsible for distinguishing tastes. This view shows the ducts which carry digestive enzymes along the tongue. The enzymes are used to pre- digest food, which is then 'mopped' up by the labella in liquid form. Research has shown that flies are able to taste a wide variety of flavours, and are especially adept at distinguishing between bitter flavours. Magnification: x400 when printed at 10cm wide.