No, a hamster doesn't need a large cage. But a travel size cage is too small that it'll kill your hamster. So a Critter-trail cage is just fine, or a 10 gallon aquarium. If you wanted you could buy a large cage to make it like their real habitat in the wild. In the cage you need bedding, hiding huts, a nesting box, food dish, water bottle, food, water, treats, wood chews, and tubes to play in.