Verified answer

yep.. do both.

the professor missed it on the 'spit' part tho.. flys 'urp' up the content of there stomach, they don't 'spit'.. it's vomit.

that urp is partially digested yummies.. the fly picks out the choicest morsels in the puddle and slurps them back up, another round for the road [ sorta ] in it's stomach..

the liquid remaining is then wiped over its extremity's and body parts and absorbed, for its moisture and its lovely [to a fly, anyway] aromas... perfume.. deodorant.. ya gotta smell good to get lucky, ya know?

next time ya see one setting on your peanut butter sandwich or coffee cup rim washing its face, just remember romeo and julliet.. or any romantic story, and how that tiny little hero is settin there dreaming of it's next affair!

Yes and yes, just like humans there poop comes out of there colon and there spit comes out there mouth.

they spit to clean them selves like cats do they lick there arms and rub it all over there face.

And any thing that eats also poops or deposits waste.

I really hope this helped :)