I did see
this post but I don't understand what this user means:
Click here to view the secret text
×You must clean entrance to queens from roaches, kill queen(s) you can access. then repeat process till all queens in left side are dead. Remember you can "store" some roaches in 2 tile wide column in top left corner of room. To clean entrance you must going back and forth in row below queens (this one with checkpoint).
I see the two-tile wide column, but I'm not sure how storing roaches there helps. Even with that full, I still can't get up there without dying.