OK, I think that networks and ecologies share properties in common. That's why I employ the ecology metaphor from time to time when talking about networks. But that said, you can't just take any old collection of things and call it an ecology. Ecologies have as defining features the lack of a central authority and the lack of planning or purpose. Ecologies are composed of autonomous, interacting, entities. You can, technically, bild an ecology, though historically this is difficult and rarely successful (Biosphere 2 was one major example). When you create things like ant farms or communities, you have something more akin to 'walled gardens' - not ecologies at all. If you model your community on an anthill - or some other construction - that's fine, but then (to my thinking) you have built a group, not a network. A farm or factory, not an ecology.