Since the release of Ditto in Pokemon Go, I have managed to catch a couple of the sneaky little insert expletive.

But instead of wasting all of my Pokeballs catching every single Pidgey, Rattata, Zubat and Magikarp... is there a way to tell if that Pokemon is a Ditto or not? I'm talking about once I click on the wild Pokemon and it's on my screen ready to be caught.

I did see this question here, but it only asks about seeing Ditto on the radar. And this question but it's in regards to catching the Ditto.