Leeches are common problems in wet areas and it is not unusual to find them living in the muck at the bottom of a man-made pond. While they can be eaten by sunfish, koi and other decorative fish, it is important to remove them if they become too numerous or if they start to overwhelm the pond. A leech trap, used regularly, cuts down and even eliminates the leeches in your outdoor pond.
Turn a large metal coffee can on its side.
Pound the nail into the side of the can using the hammer, making a puncture in the side of the coffee can.
Cover the sides of the coffee can with holes. The holes should be between 1/8 and ¼ inch in diameter and there should be a ragged edge of metal pointing inside the can from the puncture mark. You need about 50 holes in the sides of the can.
Place about ¼ cup of raw ground meat in the coffee can. The meat can be chicken, pork, or beef, as long as it is raw.
Snap the plastic lid back on the can.
Place the can on its base in the muck of the pond.
Weigh the can down with a large rock on top.
Empty the can of leeches two or three times a week, replacing the meat if necessary.
Keep the trap in the pond, moving it from time to time until the leeches are gone.