In seconds, its teeth will cut through your skin. Its suckers will stick into your raw meat, draining blood from your body. And there are millions of them! Could you survive this? Let’s see.
There are about 650 species of leeches. They can be as small as 15 mm (0.6 in) long or as large as 45 cm (18 in), like the Giant Amazon Leech. They have a sucker at both ends of their body. One of them contains the mouth, which secretes a strange type of saliva that numbs its prey. So, you won’t even notice when they bite into you and start sucking your blood. The saliva will also dilate the blood vessels to increase blood flow, so they can drink and drink again, until they quench their thirst for blood.
How many leeches would it take to kill you? How long would it take them? And how could they sneak into your intestines?
Step 1: Freeze
The average pool holds about 28,000 liters (6,400 gal) of water. But this time, the pool is filled with 9 million thirsty leeches. So, don’t make any sudden moves. Leeches use the disturbances in the water to find their victims. Juveniles generally attach to fish and amphibians. But adult leeches, like these ones, prefer luscious, juicy mammals, like you. So, hold your breath and don’t move.
Step 2: Cover your cavities.
Leeches eat slowly, so it can take them up to 45 minutes to quench their thirst. And they carefully choose where they will bite you. They typically target the groin, between the toes, armpits, and hard-to-notice crevices. And remember, their numbing saliva will prevent you from feeling the bite and realizing that leeches are draining your blood. They can even get stuck inside your mouth and nostrils and kill you by suffocation. So, cover your crevices and don’t open your mouth.
Step 3: Do the math
A human adults has about 5 liters (1.3 gal) of blood in their body. An adult leech drinks 5 to 15 ml (0.84-2.5 tsp) of blood per meal. It would take over 300 of these little bloodsuckers to suck you dry, but humans can’t survive after losing 40% of their blood. So it would only take about 120 leeches to kill you. In 2008, a 65-year-old man in Turkey rushed to an emergency room due to unstoppable bleeding. Doctors found 130 leech bites all over his body. Fortunately, the man survived after receiving eight units of frozen plasma. Would you mind counting how many leeches have already attached to your body?
Step 4: Don’t Rip Them Off
Don’t panic and try to rip them off your body as they hook into your skin, which would seriously hurt you. Common remedies include putting salt, lemon, or fire on them to force them off, but that would make them vomit on you, and possibly infect you with bacteria. Instead, find the leech’s mouth. It’s on the thinnest part of its body. Use your fingernail, credit card, or a sharp object and gently push the mouth out of your body. Do the same with the sucker on the leech’s other end. Then wash the wound and apply alcohol or hydrogen peroxide to prevent an infection.
Step 5: Don’t take a sip.
If you’re swimming, and water splashes into your mouth or nose, leeches can enter your body and feed on your blood. In Africa, people have died from anemia caused by drinking leech-infested water. In 2004, a 15-year-old girl in Tanzania had severe anemia and cardiorespiratory distress. After three days in the hospital, she vomited, and a small water leech came out. Doctors concluded that she drank it from a leech-infested water source without even realizing it. After barfing out the leech, she began to recover. So, don’t take a single sip of questionable water.
- “Switching senses: Leeches shift the way they locate prey in adulthood”. 2021. Sciencedaily.
- “Why you shouldn’t salt a leech that’s sucking your blood”. Emily Chung 2021. CBC.
- “The List: 5 Weirdest Worms At The Smithsonian“. Megan Gambino. Smithsonian Magazine.
- “Leech bites: massive bleeding, coagulation profile disorders, and severe anemia”. Kose, Ataman, Suat Zengin, Beril Kose, Nurullah Gunay, Cuma Yildirim, Hasan Kılınc, and Ismail Togun. 2008. The American Journal Of Emergency Medicine 26 (9): 1067.e3-1067.e6. doi:10.1016/j.ajem.2008.03.022.
- “Aquatic leech infestation: a rare cause of severe anaemia in an adolescent Tanzanian girl”. Kr�ger, Carsten, Isaack Malleyeck, and Ole H. E. Olsen. 2004. European Journal Of Pediatrics 163 (6): 297-299. doi:10.1007/s00431-004-1422-0.
- “Severe anaemia and death due to the pharyngeal leech Myxobdella africana”. Cundall, David B., Stephen M. Whitehead, and F.O.P. Hechtel. 1986. Transactions Of The Royal Society Of Tropical Medicine And Hygiene 80 (6): 940-944. doi:10.1016/0035-9203(86)90265-8.