Moss for Keeping and Breeding Leeches. 1 Pack contains enough to maintain about 20 leeches. Leech moss is not necessarily a mandatory prerequisite product for leech maintenance and care, but rather, its an optional extra. If you happen to be an avid leech lover, leech collector, a leech pet keeper or an aspiring leech breeder, you might want to use leech moss for your lovable animals. Although Hirudo Medicinalis and Hirudo Verbana medical leeches can live perfectly well in plain tap water, if you add leech moss as bedding and add other aquatic flora and fauna to their aquarium you are stabilizing their environment, making it as close to their original habitat in the wild as possible, mimicking their leech lakes or pond surroundings. Hirudo Leeches feel happier with leech moss and they tend to snuggle and hide inside it, stretching their bodies out and enjoying the moist dampness and sponginess that it can offer. Perhaps the aroma is quite calming for them as well. This natural moss provides a comfortable bed for pregnant and mating leech mothers to lay in, as well as for Hirudos who are being bred and multiplying, in the process of laying eggs and when the pregnant leeches’ cocoons are hatching and baby leeches (hatchlings) are being born and crawling out of their spongy eggs. This pack includes one ball of moss, which will multiply and grow quick with time.