Swimming among the lampreys can be disquieting. With bodies like eels' and mouths like leeches', it's all too easy to imagine one attaching to your body and piercing your skin. Lampreys have a voracious appetite for blood, but fortunately for humans, they have a strong preference for meals of the coldblooded variety.
Attacks on Humans
A lamprey has the physical ability to attach to a human but is extremely unlikely to do so. The lamprey feeds on fish, which are coldblooded, and so a lamprey searches for this type of prey and not warmblooded humans. It is possible that a starving lamprey might turn to a human for a meal, but is not likely to pierce the skin due to the difference in texture and temperature from his usual source of food. If a lamprey does attach to a human, it can be removed by raising it out of the water, which will cause it to suffocate.