@Genevieve4 It's because the nose is too small. I'm not sure what it is about aliens, but the game treats them weird.
I always change up my alien looks b/c I don't like their default look.
If you click on the nose, notice which nose they have in the options, then click on whatever nose is highlighted (or choose one you like) you should be able to get a nose big enough to accommodate a nose ring if that's what you are looking for.
I do this to the chin too and make the eyes smaller and usually give them eyebrows b/c well...eyebrows 🙂
HAPPY SIMMING!
