Board Thread:Questions and Answers/@comment-27869969-20160226053354/@comment-1781513-20170630174511

From what I can tell (I haven't watched the show in ages, so this might not be 100% accurate) they appear in SGU episodes "Awakening" (S02E03), "Resurgence" (S02E10), and "Deliverance" (S02E11).