The mice aren’t in seasons 4 or 5 because they left the team with Keith to join the blades of marmora. Like I can see them helping him break into places and him giving them a little bed or something in his room at the base. Then one day Krolia walks in and just sees all the mice crawling on Keith and is just like… “I really never should have abandoned you.”

Also can someone please do a fan art of Keith in the BOM with the mice. I need that in my life.