Something grows in them.

Intelligence in Urd Prime is not a stat. It develops. What becomes possible as it does — that's something your creatures will show you.

Some things are meant to be found.

The Shee left records. Most of them were written for minds ready to receive them. The wiki documents what can be observed from the outside — species, world, biochemistry, history. What intelligence unlocks as it grows is something the creatures of Urd Prime discover for themselves. So will you.