Id get like 6 females and 2 males to start. They reproduce every month if done right. If you get to many sell em, dubia are popular feeders. But i dont think you will get overloaded with them. I have a small colony for my 4 spiders and they dont breed as much, to keep them from breeding to much i keep them in a small sterilite tub, the smaller the space the less likely they will reproduce.