Good luck with your avocado trees. When I was a little boy, we got an avocado pit to sprout in our apartment and put the seedling into a flower pot. By the time I left home, it was up to the ceiling. No avocados--I think it needed some cross pollination. But it was a beautiful tree.
Yes, Avocados do have special polination needs, and without bees and other insects in your house it wouldn't do well. Haas is the most popular avocado because of its ease of peeling and the nice taste and texture. But a grove of Haas avocados does not self-polinate well.
I'm not an expert at this by any means, but what my rancher friends tell me is that you intersperse "breeder" avacado trees throughout your avocado population. I have a "Zutano" avocado tree with three Haas and one Lamb Haas around it in the shape of a "W", with each tree 20' from its neighbors. The Zutano is the breeder for the four Haas. The single Lamb Haas is to lengthen the harvest season because it ripens later than the Haas.