Those strange metal collars wrapped around tree trunks may look like part of the tree itself, but they actually serve a practical purpose. Known as tree baffles, these smooth metal barriers are designed to stop squirrels, raccoons, and other climbing animals from making their way up the trunk. Because the surface is difficult to grip, animals struggle to climb past the barrier and reach the branches above. This can also help prevent them from getting onto nearby roofs, where they may cause damage or find ways into attics.

Different types of baffles can be used depending on the size and age of the tree. Wide metal bands are commonly placed around larger, established trunks, while cone-shaped versions can be useful for younger or smaller trees. Some can even be painted or finished so they blend more naturally with the surrounding landscape. They aren’t meant to repair damaged bark or strengthen the tree. Instead, they’re a simple physical defense against unwanted climbers. So the next time you spot a shiny metal collar around a tree, it may not be protecting the tree from the weather at all—it could be keeping a clever little intruder from climbing any higher.