I kept my girls together from the day they hatched until about 4 weeks ago. They ate fine (I always fed them in the "Rodent House of Death", as my kids call it), have had no health problems, and they are two of the most even tempered, easy to handle snakes in the world. Of course, today I took delivery of four males, so now everyone has their own home. I would never consider putting any of the others together (other than at that "special time"), but the girls never knew anything else, and seem none the worse for the wear.