when they are babies they are usually housed in big bins together but i think at around a month-2months old they should be kept in a screen enclosure. I havent taken care of anything younger than 2 months so im not entirely sure. Other members will definetly let you know
As said, you can house them in many things when small. You just want to make sure there is plenty of air flow with whatever you use. Say you use a critter keeper. You dont want to cover the whole thing with the lights you will want at least half of the enclosure open if it is not screened on any sides.