Dog tapeworm head. Coloured scanning electron micrograph (SEM) of the head (scolex) of a dog tapeworm (Taenia pisiformis). This tapeworm has dogs and foxes as its final hosts and rabbits and hares as its intermediate hosts. The hooks at the tip of the scolex (red) are used to anchor the worm to its host’s intestinal lining. It does not possess a digestive tract and so absorbs nutrients from the half-digested food of the host through its skin. Magnification: x75 when printed at 10 centimetres wide.