I keep finding mushrooms all over my town what do I do with them?

There a few different kinds, but you pretty much just sell them. You'll get 5 (?) a day, every day of November. 1 of those will be a piece of mush furniture. You can keep the furniture or sell it, and sell the mushrooms for extra cash. There is one kind of rare mushroom that you must dig up.

Flat Mushroom - 200 bells
Round Mushroom - 200 bells
Skinny Mushroom - 300 bells
Elegant Mushroom - 10,000 bells
Rare Mushroom (in the ground)- 16,000 bells

PS. I think you need perfect town status for rare mushrooms to appear.

So do these mushrooms last the whole day?

And if you don't pick them that day, will you have double the mushrooms the following?

I remember on the original Animal Crossing. Mushrooms vanished every 15 mins starting from 8:30am, there was no mushrooms left by 11am.

they do not vanish. you could have up to 150 (Guestimate) in your town at the end of november.

quote DXD

quote Apldom

PS. I think you need perfect town status for rare mushrooms to appear.

So I may as well kiss these items goodbye for the time being.....

Heh. Not when a good friend of yours can give you one