I just finished all the levels in the game and wanted to go back and finish getting the moths that I missed. On the hub world screen, it looks like it shows (above the door for a particular level) if you've gotten a moth in that level. I was hoping there would be something analogous (like an outline of a moth) to show which levels you've missed them in, since only 10 of the 24 levels in each world actually have moths. 
 
Wasn't sure if I was just being dense, or if I'm going to have to look up a list of the levels online somewhere, so I don't have to replay every single level. Not a huge deal, was just curious.

Once you get 15 moths, your "prize" is the ability to see which doors contain a moth you haven't found yet.

Once you get 15 moths, your "prize" is the ability to see which doors contain a moth you haven't found yet.