Fence
From PinataIsland.info, the Viva Piñata wiki
You can isolate a piñata or its house in a certain place with fences. These fences can be used to separate different piñata species that don't get along, protect your crops from hungry pinatas or to stop a piñata, like the elephanilla, from wreaking havoc on your garden. There are different types of fences like wooden or stone fences.
File:Stone fence.png
A stone fence
File:Picket fence.png
A picket fence
File:Wood fence.png
A wood fence