Special care and attention should be taken if the leeches are to be used in a heated hospital ward. Keep them as cool as possible until they are needed. Never put leeches into direct sunlight. The water is now ready for use. Aeration is unnecessary.
Leeches are amphibious and like to crawl about.
Perforations are advised but they must be very small indeed, as the leech body is elastic and capable of going through remarkably small openings. A cloth cover secured tightly with string, rubber band or tape is useful. Do not overcrowd. The greater the amount of water, the less it needs changing. No more than 50 leeches should go into a 2.5 litre container.