I was checking in a guest tonight and they asked if Bug was ok. I said sure, having seen her earlier that day. They mentioned she was lying at the bottom of the cage. Not a bug thing to do. So I had a look and sure enough Bug had passed away.
Although a crazy budgie, and probably the murderer of Blue, Bug was a nice little bird. Slightly confused and thinking humans were a better mate than budgies, she even laid for a while. She loved her log that she completely hollowed out. So I put her in her log and have to go and bury her in the budgie cemetery.
The bay window will never be looked at the same again.