All leeches are very extensile and can contract the body to a plump, pear-shaped form, or extend it to a long and worm-like shape.
Small leeches taken into the mouth with drinking-water may give rise to serious symptoms by attaching themselves to the fauces and neighbouring parts and thence sucking blood.
The rivers and lakes yield enormous quantities of fish, and leeches also are plentiful.
Leeches are usually olive green to brown in colour, darker patches and spots being scattered over a paler ground.
Earthworms, leeches, lugworms and marine worms bryozoans Bryozoans look like plants but actually consist of thousands of tiny animals.