Wondering if the post office is open on July 4, and if the letter carrier will deliver the mail on Saturday? Although most retail stores and restaurants will be open on Independence Day, the U.S. Postal Service will closed down for the day.
Leeches are famous as blood-suckers. The species that feed on blood have special chemicals in their saliva that prevents blood-clotting. Many blood-feeding leeches attack only fish, a few attack any vertebrate (including people), and a few are specialists on another group of animals, like turtles or waterbirds. There are also lots of leech species that don't suck blood. They are predators, eating worms, snails, aquatic insects, and other invertebrates.
The leeches are then allowed to extract blood, for 20 to 45 minutes at a time, from the person undergoing treatment. This equates to a relatively small amount of blood, up to 15 milliliters per leech. Medicinal leeches most often come from Hungary or Sweden. There are several situations in which leech therapy may be used.