Leeches fear table salt and quicklime the most; master the methods to control them easily

The leech, scientific name Hirudo, is a type of annelid that lives in freshwater or moist environments and feeds on the blood of humans and livestock. It has strong suction ability, and after being bitten, the wound is often difficult to stop bleeding. In aquaculture ponds for raising eels, fish and other aquatic products, it also bites fry, affecting breeding profits, so it is necessary to understand its weaknesses.

What leeches fear most is table salt. Its body surface has no hard shell protection, and the whole body relies on body fluids to maintain balance. Once salt is sprinkled on it, the water outside its body will be lost in large amounts due to osmosis, and the body will quickly dehydrate, shrink and eventually die. This is also the most commonly used emergency method after being bitten by a leech. Sprinkling a little salt can make it fall off on its own. Never pull it off forcefully, to avoid the mouthparts breaking off in the skin.

Besides table salt, leeches also fear quicklime and dry environments. Quicklime releases heat when it meets water and is strongly alkaline, which is very irritating to leeches. It is often used to disinfect and kill leeches when clearing aquaculture ponds. At the same time, leeches cannot do without moisture, and under high temperature and strong sunlight or dry conditions they easily lose water and die, so turning and drying the pond bottom and keeping the environment dry can also effectively reduce leech breeding.

In aquaculture, leech control should focus on prevention. Fine gauze can be installed at the water inlet for filtration to prevent wild leeches from entering with the water; before stocking fry, use quicklime to thoroughly clear the pond. If leeches are found during the breeding period, drugs safe for the cultured animals can be used under the guidance of technicians. Frequently patrolling the pond and promptly removing weeds around the pond can also reduce opportunities for leeches to hide and reproduce.