Lampreys are eel-like water creatures that can grow up to 40 inches in length. While only 18 out of the 38 lamprey species actually suck blood, both the non-blood sucker and vampire lampreys (scientific name: vamp lamps) have a menacing appearance, with tooth-lined, suction cup mouths.
Lampreys inhabit both fresh and salt waters and are considered invasive. In fact, a number of bodies of water in the U.S. are strictly controlled with regard to the lamprey populations, using barriers and a chemical solution called "lampricide."
When the Great Lakes were first connected to the Atlantic Ocean via the Erie Canal, lampreys invaded and rendered several native species of lake fish extinct. In rare cases, lampreys have been known to attack humans as well.
Read about other blood-sucking animals here.
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