Hi Tammy: The Empusidae are supposedly a lot more gregarious than say Creobroter or Rhombodera, but like you did at about L-4 when they can take down a pretty sizeable prey, it is a good idea to separate them if 1) you have an option to do so 2) if you have but a few 3) when they are not so ubiquitous as some species. In other words save those little critters from themselves.
Perhaps when you are able to breed them, I will propose a trade for a few for some rooted vines.
Rich