Only female mosquitoes feed on human blood to produce eggs, making them carriers of diseases like yellow fever and malaria, posing a significant threat to human health globally.
Historically linked to the spread of the bubonic plague, fleas are bloodsuckers that transmit diseases by feeding on infected rats and then humans, causing massive epidemics.
Bedbugs are nocturnal parasites that feed on human blood, leaving painless bites due to an anesthetic in their saliva, leading to itchy welts; fortunately, they do not transmit diseases.
Found in Africa, oxpeckers are known as tickbirds, cleaning parasites off large animals like buffaloes, though controversially, they also feed on the hosts' blood, hindering wound healing.
Galapagos' vampire finch supplements its diet of seeds and insects with blood, often from booby birds that tolerate the finch's feeding behavior.
Used historically in medicine to treat various ailments, leeches are now employed to improve blood circulation after surgeries such as limb reattachments, showcasing their medical utility.
Jawless and ancient, lampreys latch onto fish to suck blood and tissues, remaining attached for extended periods, though they rarely pose a threat to humans.
The only mammal to subsist entirely on blood, vampire bats typically target livestock but occasionally humans, using sharp teeth to create tiny wounds and sharing blood with group members.