small leech crawls over bare soil in search of moisture.

alternative ancient animal annelid background black blood bloodletting care clitellum closed comprise dangerous detoxification disgust doctor education fluke glass healing health hematophagia heparin hermaphrodite hirudinea hirudo hirudotherapy invertebrate jar leech leeching medical medicinal medicine nature parasite physic plastic pot research science skin slice sucker sucking therapy water wet worm zoology