All TriCo students enrolled in a Swarthmore course receive Swarthmore usernames and passwords that they use to log into Swarthmore's Moodle site. If a TriCo student is officially enrolled in your course, they will automatically be added to your Moodle course roster. To access your course, the TriCo student should log into Swarthmore's Moodle site (https://moodle.swarthmore.edu) with their Swarthmore username and password.
To add a Haverford or Bryn Mawr student who is not enrolled in a Swarthmore class, you can turn on guest access to your course. Most faculty set up a guest password to protect the contents of their Moodle course. For more information, see How do I make my course available to students or guests?