Geese are sometimes used as guards due to their great eyesight, territorial nature, and ability to detect people or sounds.

The analysis reveals that some geese are employed as guards due to specific behavioral traits. The first claim confirms that geese are used effectively as guards in some places, such as prisons and border areas, supported by evidence from medium-quality sources. Geese's eyesight is shown to be excellent and wide-ranging, corroborated by multiple sources. Their territorial nature is highlighted during breeding seasons when they become aggressive to protect their young. Lastly, geese can detect unfamiliar individuals or sounds, supported by their excellent sight and adapted hearing capabilities. These traits collectively make geese viable alternatives to traditional guard animals in certain scenarios. All claims have strong evidence, resulting in high confidence in their factual accuracy.