We remove the male and use the 12 week cycle listed in the sticky's. So far it has worked well and we are on litter 5 or 6 with more prego's ready to pop! The only babies eaten seem to have been one or maybe two out of one or two litters. Probably becouse they were not doing well. We are now working on a second colony of rats that will be rats born in our care so we can track ages better and handle them more often from pups up to make tamer breeders!