150 Live Leaches, Size: MINI. Mini Leeches are a bit larger than baby leeches and smaller than small or cosmetic leeches. There is no guarantee whether these leeches will be able independently. If they do not feed, you can wait for them to grow a couple of months and feed them or you can buy large leeches simultaneously and these mini leeches will feed in the place where the adult leeches fed. This is done until they grow larger and stronger and are capable of feeding on their own.