My chooks have a feeder inside their house, but never seem to bother with it
I throw a couple of handfulls of mixed grain and layers pellets into their run of a morning and they spend all their time scratching and picking it up - there's never any left, but that might be because the little garden birds can get through the fence and 'help' with the cleaning up. It might be worth only putting enough for a day at a time into the feeder, that way they'll get into the habbit of pecking up the stuff that's on the floor.
The cockatiel in the cage in the house is a different matter altogether though, he can throw his seed up to 4 feet from the cage if he's in the mood
I think birds are just plain messy