Deliver crates of milk to residential houses in Flowerberg and get milk caps from their tenants in return. Once you've delivered the crate of milk, wait for a while to give the tenants time to drink their milk; then you'll see a clickable milk cap icon next to the building.

You can collect milk caps along with collecting profits from the building. You can also get milk caps in exchange for certain resources at the town bank.

Milk caps can be used to buy a range of items at the town hall. The town hall shop offers such plants as golden and pink trumpet trees, royal poincianas, bleeding hearts, passion flowers, sweet peas, morning glory plants, scarlet milkweed, and native frangipanis; you can also buy decorations here, such as 'Geometric', 'Clover' and 'Lotus' tiles, flower tiles, 'Circles' tiles and brick paving.