Feathers you find can be kept as long as it's legal and ethical. Certain feathers, like those from protected bird species, are illegal to possess without proper permits. Before keeping feathers, research local laws and regulations to ensure compliance. Additionally, consider the feather's condition. Feathers that are damaged or dirty may not be suitable for keeping. If the feather appears healthy and intact, you can keep it as a unique natural find, use it for crafts or decoration, or study its characteristics. Remember, feathers play an important role in the ecosystem, so leaving them where you found them is also beneficial. Ultimately, it's up to you to decide whether keeping a feather brings joy and curiosity without causing harm.