Hi guys,
I've just published an update that changes the game so that you have to feed your pets in order for them to continue producing coins.
While the pets produce coins their hunger value increases and at some point they will stop making coins. You can see that they are hungry/angry when they have a cloud on their heads. You can obtain food for the pets in the shop using coins. Each pet has their special food and does only eat that particular food. Feeding works by approaching a pet and dropping/throwing the food using the THROW key. The game automatically checks which pet is the closest one and thus selects the appropriate food to drop automatically.
Have fun!