eating poop

I just got home and Mickey was eating his poo! He's been doing this all day even after I've cleaned out his cage TWICE! He's been eating it for the past few hours, is there any reason why he's doing this even after I've given his cage a good clean?

Rhodie is a 4-month old normal grey and she's only been home for a month. (She has not been DNA tested, so she could be he.) She was fine Sunday, maybe just a little less vocal and active, but nothing major. I woke up Monday morning to see that she had thrown up throughout the night and there...