Minuscule minions in others spaces
I'm looking to play a Circle of Spring summoner in an upcoming game, and I'm confused a bit by minion size abilities. Almost all of the Spring minions are size 1T, so tiny but they take up one square on the combat map. They also have the ability Minuscule, "has cover while occupying a larger creature's space". If they all take up one square, when would they be in a larger creatures square? I've spent a few hours trying to look up how size rules relate to this in the codex compendium and drawing blanks so any help or guidance would be appreciated