Leeches
- The leech is another common annelida like the earthworm.
- The leech is a blood sucking worm that can harm and help humans.
- While it does cause many diseases, it is also used at hospitals when something needs to be taken out of there blood.
- The leech has no respiratory organs.
- Its skin does the gas exchange.
- Oxygen is taken in, and carbon dioxide is released.