Just tap on the fences to remove them, but keep in mind that you can't have more dogs than cats, or cats than rats, in the same pen. Avoid chaos and conflicts by carefully choosing in which order to removes the fences.
The game gradually becomes more and more complex as it progresses. The shape of the farm changes, number of fences and animals varies, and new species of animals are added. Each new animal changes the hierarchy, which is shown at the top of the screen.
Plan a clever strategy -before you start removing fences- and unite all the animals in Animaze.