It’s a question that sounds like it belongs in a horror novel , yet it taps into real biology and real concerns about what happens when a parasite feeds on contaminated blood . TO THE LEEECHES.. Today they will have a chic choice in terms of food. The blood of a drug addict, a drunk person and a heavy smoker. What If a Leech Is Given The Blood Of a Drug Addict To Drink? Leeches are simple creatures—they don’t filter toxins , process drugs, or reject what they consume. They simply attach, draw blood, and store it. So if a leech drinks the blood of a drug addict, everything in that blood enters the leech’s body exactly as it is: opioids , methamphetamine residues, cocaine metabolites, alcohol, pharmaceuticals , or any combination of chemical substances . Inside the leech, the blood sits in internal storage organs where it can remain for months without being digested. This means the leech essentially becomes a living reservoir of whatever was in the host’s bloodstream at the mom...