1, dry lime powder: The most effective and pollution-free way to kill leeches in a large area is to sprinkle dry lime powder. Leeches will fester and die after being polluted by lime powder, and will also die of physiological acid-base imbalance in alkaline water with lime; However, the strong alkalinity of lime can only be maintained for a short time, and it can be diffused and desalinated after pest control, which is also beneficial to the improvement of strongly acidic old swamp soil.

2, salt: Leech is a mollusk, without skin protection, skin is the first protective barrier of animals, because there is no skin, so it is very sensitive to salt. After leeches are sprinkled with salt, the salt and their body fluids form high-concentration brine, which will contract under pressure, prompting the body fluids to extravasate, leading to their dehydration and death. Therefore, don't panic after being bitten by leeches in the wild. Drop high-concentration salt water on leeches, and they will soon loosen the sucker and fall to the ground to dehydrate and die.