Darkfield and fluorescence light micrograph of a tick (family Ixodidae) from above. Ticks are blood-sucking parasites of warm-blooded mammals, including humans. They use their sharp mouthparts to pierce the skin. Ticks are vectors for a number of animal and human diseases, including Lyme's disease. Microscopic contrast method: Epi-Fluorescence, blue excitation. Magnification: x15 when printed at 10 centimetres wide.