Seems if you enter and exit the house at just the right times, you can manipulate the music so that what is normal outside music plays instead of the exclusive inside music.
if you're going to make the bear rug reward us with 100x clicks' worth of chills, how about making it match with whatever the best investment income is? the click income is still quite lackluster at high spirit levels just like outside.
one more thing (for now): since the inside of the house looks like only the front room and the outside of the house looks like it has many more sections to be seen than that, I'm thinking that there could be a new area for each room that you could spend up to a year decorating each and release each new room every Halloween until after as long as a decade, the entire house is fully ready to collect screams.
also, I just now confirmed that the black dot does in fact feed every skull; now to double check whether or not it will or won't feed the full-body skeleton hanging from the chandelier.
btw, i'm a little surprised that some of the sound effects of winning certain investments from scratch tickets sometimes differ from what milestone you're actually at. I have been hearing piano sounds when I should be hearing organ sounds and wisp sounds long before I even got to ghoul 600 when they're supposed to be heard.
gonna have to rewrite the above top rated comment about what to feed who soon. The cupcake feeds the ghost and the black dot thing feeds skull number 800 on the top shelf.
speak of the devil, the black dot feeds skull number 800 on the top bookshelf. I don't remember if it works or not on the other skulls; going to check again
still no clue what that black/gray dot from the butler is for and the cupcake as well. And what to feed the skeleton? Some items listed in the above high-rated comment didn't work for me.
 "Scream Collector"){kind=icon}
 "Christmas cat"){kind=icon}
It's completely random. Some times you will get more cheese than mouse traps