There are four birds on the new $50 note unveiled by the Reserve Bank of Australia (RBA) today, but we're confident you'll only be able to spot three.
That's because the fourth can only be seen under ultraviolet or UV light.
See if you can spot where it's hidden below.
If you look closely, you can see there's a green swan in the left-hand corner of the side that features inventor and author David Unaipon.
And there are two more black swans on the clear window that runs through the middle of the note, which are also visible on the side that features Edith Cowan, the first female member of an Australian parliament.
But the fourth swan is hidden behind the signatures on the Unaipon side.
Here's what it looks like under a UV light:
"It's a covert security feature because it's not obvious to the immediate appearance of the note," RBA assistant governor Lindsay Boulton said.
"When a UV light is shined on it, an image shows up … and that makes it quite difficult for counterfeiters to replicate."
The UV feature was also included on the new, already-released $5 and $10 notes, with an invisible eastern spinebill on the $5 and a cockatoo on the $10.
And the other features you're probably familiar with by now — including the clear window, the tactile texture, and the rolling colour effects — also made it onto the $50.
They're not pineapples
While it may look like there are several yellow pineapples on the new note, they are not a subtle reference to the note's colloquial name.
We double checked with the RBA and they're actually sprigs of wattle.
"It's an interesting comment. No, it's certainly not intended to represent a pineapple," Mr Boulton said.
The new note will go into circulation from October this year.