Green Poop

[Marzipancake]

I noticed bright green poop this morning in my chicken run. This is the only one green dropping in the area. I have 4 chickens and a goose currently in this section and everyone is acting normal. What could it be??

 

[Wyorp Rock]

If it's a one time thing, I'd just watch everyone to see if they are acting o.k.

Do look to make sure no feed has spilled on the ground and it's moldy.