Flum's Fountain is a place owned by Flum, better known by Scribbles and built by Rigg Bin Weevils visit Flum's Fountain to chat with their Bin Buddies and other Weevils. Bin Weevils also earn Mulch and XP when growing mushrooms.
Bin Weevils earn Mulch and XP by growing mushrooms. To do this, the weevil needs to squirt jets of water at the mushrooms. To do that, the weevil must jump on the blue highlighted border of the Fountain when it pops up. Bin Weevils will need to be quick as they only stay up for 5 seconds. This is better for weevils who have unlocked the 'Fast Move' action.