You never want to house several hamsters in the same cage, no matter what breed you choose or how large the habitat is. For example, when housing Robos together, avoid housing more than three pairs together and choose a 20- to 30-gallon tank for their habitat. You can also protect the colony by providing multiple toys, burrows, feeding dishes and water bottles. This helps ensure the animals don't fight. Lastly, always keep an eye on your hamsters during the first few weeks to ensure the hamsters are getting along. If any hamsters seem to be sitting alone, they may not be a good fit for the colony and will need to be rehoused.