Based off the network you have set for your Facebook profile, this can either be a geographic location or a company you are employed by. Additionally, there is a "Unassociated" network for people that have not specifically set a network or refuse the application access to this data.

Hatchlings only recognizes one network per person. If you want to change your network, you first change it with Facebook, then click the "Refresh Network" link on your own basket.