Have you ever wondered why hippopotami spin their tales when they defecate? African Bushmen say that they are showing God that they have eaten only grass and not fish as fulfillment of the condition under which they were allowed to live in the water. But modern science has other ideas. Hippos can be infested with a leech that has the same brown coloring as the hippo so birds do not find them. They actually live inside the hippo after crawling through the anus into the rectum where they reproduce. When the hippo defecates, the leeches are squeezed out and the hippo whirls its tail to make sure the little blood suckers do not crawl back in.
While hippos may find leeches annoying, plastic surgeons these days are looking at them with admiration. Not only are they looking at the leeches, they are using them in their practice. Now, the use of leeches is nothing new. The ancient Greeks thought they were helpful in sucking out disease and the little critters were used for this purpose on and off throughout history. But it was in the eighteenth and nineteenth centuries that "leechmania" developed. Diseases were thought to be caused by excess blood and patients were bled and leeched. Some of the therapies were quite imaginative. Tonsillitis was treated by lowering a leech on the end of string down the throat. Feminine complaints were similarly approached, this time using a different bodily orifice. Such treatment was reserved for married women only.
We are now past this kind of nonsense, but a patient who has had a finger reattached or a skin flap used to reconstruct a nose may very well wake up with leeches dining on the affected body part. While arteries can be readily connected through microsurgery, veins prove to be more difficult. Blood can therefore pool and form clots which can cause severe complications. Leeches solve the problem by acting as artificial veins while the tissues grow new veins with a few days. Leeches are cheap and easy to maintain. Patients don't mind the technique because the alternative may be loss of the reattached tissue. Sometimes they even give the leeches pet names. There is one thing that has to be watched though. After dining the leeches like to crawl into dark spaces to digest their food and rest. So you've got to take care. Remember that humans, unlike hippos, have no tails to protect parts of the anatomy that may seem inviting to leeches.