Ключевые слова: aid, alternative, ancient, animal, annelid, annelida, anxiety, black, blood, bloodletting, bloodsucker, bloodsucking, care, clitellum, closed, dangerous, disgust, doctor, earthworms, glass, healing, health, healthy, heparin, hermaphrodite, hirudotherapy, invertebrate, jar, leech, leeching, medical, medicinal, medicine, nature, parasite, pot, science, segmented, skin, slice, specimen, stained, sucker, suction, therapy, water, wet, wildlife, worm, zoology,