A study of the stomach content of some lampreys has shown the remains of intestines, fins and vertebrae from their prey. Although attacks on humans do occur, they will generally not attack humans unless starved.

Can a lamprey kill a human?

While they prefer fish, and won't come after we humans with nearly the same ferocity as they do aquatic creatures, there are accounts of lamprey attacks on humans. ... Despite this bizarre account, experts suggest these creatures would only attack a human out of mistaken identity.

Will a sea lamprey attach to a human?

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.