Single bees will last a few months at best, to keep bees you need a hive. I have heard that there are some types of stingless tropicals that are available but have never seen them. They are used in hothouses and arboretums, or so I have been told.
My parents bought me one of those kits where you raise catipillers until they turn into butterflies when I was a kid. The kits come with everything including food for the catipillers and a small green house for the butterflies. It was pretty cool to watch the whole cycle. I released the butterflies after they hatched. Don't worry guys, the species they were are native to where I live. They were Painted Ladies (Vanessa cardui).