When bots have human names and human profile pictures they are most certainly pretending to be human. But even if they do not have these, by not explicitly ment

When bots have human names and human profile pictures they are most certainly pretending to be human. But even if they do not have these, by not explicitly mentioning they are bots on social networking sites (including sites like reddit) they are effectively pretending to be humans as well, because like you mentioned people assume that other users on the site are human.