Wattle it be?

It's a trick question.

It'll be a Wattle Blue (or Miskin's Blue) (Theclinesthes miskini). It's rare in the suburbs, but because we live so close to the Belair National Park, I was lucky enough to spot this in the Park, near the gate. They breed on acacias (hence the name) and apparently they like to be with ants.

Quite small with a wing span of only 22 mm.

It's an amazing butterfly season this year. I think this must be the third species new to me this year.

That's really cool.