Leech

Leech Temporal range: Silurian – recent PreꞒ Ꞓ O S D C P T J K Pg N
Hirudo medicinalis sucking blood
Helobdella sp.
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Annelida
Class:	Clitellata
Subclass:	Hirudinea Lamarck, 1818
Infraclasses
Acanthobdellidea Euhirudinea

A leech, plural leeches, is a kind of worm that live in wet areas. Some only live in water, but some, called terrestrial leeches, can live on land. Terrestrial leeches can only live in wet and humid areas.^[1] Some leeches that live in water can swim.^[2] Leeches have 34 connected parts, called segments, that make up the body.^[2] Some leeches are predators, and eat other small animals, called invertebrates. Other leeches drink the blood of bigger animals, including humans.^[3]

1. ↑ Drinkwater, Rosie; Williamson, Joseph; Swinfield, Tom; Deere, Nicolas J.; Struebig, Matthew J.; Clare, Elizabeth L.; Coomes, David; Rossiter, Stephen J. (2019). "Occurrence of blood-feeding terrestrial leeches (Haemadipsidae) in a degraded forest ecosystem and their potential as ecological indicators". Biotropica. 52 (2): 302–312. doi:10.1111/btp.12686. ISSN 0006-3606. S2CID 201205936.
2. ↑ ^{2.0 2.1} "Leech | The Canadian Encyclopedia". www.thecanadianencyclopedia.ca. Retrieved 2023-06-01.
3. ↑ Abdualkader, A. M.; Ghawi, A. M.; Alaama, M.; Awang, M.; Merzouk, A. (2013). "Leech Therapeutic Applications". Indian J Pharm Sci. 75 (2): 127–137. PMC 3757849. PMID 24019559.