How to Remove a Leech
In a survival situation it is quite likely that you will need to cross a body of water to reach safety or supplies. For the most part such crossings will be uneventful, but in other cases you may emerge from the water with leeches upon your skin. While not immediately harmful, you'll want to remove leeches as quickly and safely as possible.
The problem with leeches is that they carry bacteria. Incorrect removal of a leech using commonly discusses techniques such as squeezing, salting, and burning can result in the leech regurgitating the contents of of it's digestive system including harmful bacteria.
Proper removal begins with identifying the anterior sucker. This is the small end of the leech. Place a fingernail on your skin directly adjacent to the anterior sucker and gently, but firmly slide your finger toward where the leech is feeding. The aim is to push the sucker away sideways. Once this movement breaks the seal, the leech will stop feeding. It will also seek to re-attach itself so continue to flick the anterior sucker.
The next step involves pushing or picking at the large end of the leech to break its seal. While doing this you may find that the short end has reattached itself possibly to your finger. Not worries as it will be easy to remove at this point. Once the leech has been completely removed, put salt or insect repellent on it to keep it from attaching again.
The wound from a leech will heal easily and quickly once the anticoagulants it uses have lost their effect. It is unlikely you will need to seek medical help for the wound. Be sure to inspect yourself thoroughly. Where there is one leech there may be many.
The Worst Case Scenario Survival Handbook - Travel by Joshua Piven and David Borgenicht