By frenzied squirrels and dropping acorns. You would not think two such relatively small items on one's roof would make such racket but indeed they do!
Having been hit on the noggin by a falling acorn I can also say IT HURTS, a lot more than one might think. Given they fall from a HUGE tree they must gather a lot of force on the way down. Kinda like dropping a penny off the Empire State.
The squirrels have lost their tiny little minds and have turned our front lawn into a minefield...LOL. I swear you'd think our winter was like "Fargo" or something! The way they panic and freak out. Fighting over ONE acorn when there are about 100 laying on the ground. They remind me of that freaky little critter in "Ice Age".

Oh yes and walking outside at this time of year without shoes? Bad idea. Broken acorns...acorn "tops" are adept at slicing feet wide open folks! flip flops at the minimum!
The leaves have not changed yet nor do they show any sign...too early. I love Fall...aside from the acorns...and extremely agitated squirrels. They make ME feel like I should be doing something more to prepare but honestly? Winter is no biggie here lol.