Humans could watch them but not necessarily interact with them. A whole spectrum of possibilities for interaction with biota exists. From worlds where they are tailored to make life interesting for human visitors as happens with the Creatures product and with the virtual fishtank Aquazone to worlds such as Tierra where we can only see statistics about their activities. We are in the early days of learning to design organisms but demand from games and simulations means there is tremendous pressure to develop companions for us in cyberspace. From talking to your potted plant and watching it grow in response, to having virtual pets, or virtual children all the way to conversing with true aliens these are the sort of things ALife makes possible in virtual worlds.
Avatars are only the beginning of living in cyberspace.
Those would be agents. But there is a possibility of developing a compound personality by using agents. A sort of recombinant schizophrenia. Then you could split off a ghost representative of yourself to do a task and recombine him with your main personality later. As we spread ourselves more thinly across the Internet we will need more AI helpers to handle the information streaming into us.