Coloured scanning electron micrograph (SEM) of the head of a tsetse fly (Glossinia sp.) with the proboscis (yellow, between two brown palps) exposed. For comparison, the proboscis is set within the tip of a stainless steel hypodermic needle of diameter 0.6mm. The proboscis is a hollow feeding tube that has small teeth at its tip (not visible), used the pierce the skin of the fly's prey prior to a blood meal. Inside this tube is a narrow capillary, the hypopharynx, that is used to inject anticoagulant saliva into the host. It is this action that can transmit the disease trypanosomiasis (sleeping sickness) from an infected fly to animals, or humans. African animal trypanosomiasis is a major cause of poverty in Sub-Saharan Africa. A hypodermic needle can likewise be used to sample blood, or to inject; drugs, anaesthetics, vaccines. The image shows the exquisite delicacy of its natural counterpart.