Student enrollments in Moodle course sites correspond with the course rosters in BearPAWS. Students who are automatically enrolled in your Moodle site(s) will have "LDAP enrollments" listed as the Enrollment method in the Enrolled users area of your Moodle site (see image below).

Students enrolled through this method cannot be removed manually.

Students who officially drop a course will be automatically removed from corresponding Moodle sites, usually within a few days following the add/drop period.

Students who withdraw are not removed from Moodle course sites.