Hopefully you will get some babies soon. It takes them a little while. You might also want to add a few more to your group so that you have a few groups mating. I don't think they eat the babies. I could be wrong, but I'm pretty sure they leave their own kind alone even if they are young. Mine too quite a few months before I started seeing babies though, so depending on how long you have had them, it might just be taking some time. Good luck with them though. 
