Sometimes some of your worms migrate to the sump which is mostly more distressing for you than them to be honest.
Try broadening your search.
Our composting worms are mixture of species (mainly reds and dendras) selected for their composting ability
The Urbalive Worm Composter is a home wormery kit that can be used indoors or outdoors for composting kitchen waste with the red worms. The perfect wormery for households, classrooms or offices.