These oil-based marking pellets are designed to mark targets or problem animals for future recognition. These pellets can leave their mark for up to two weeks in an outdoor environment. Ideal for foresters, ranchers, wildlife biologists and animal control agencies to mark trees, buildings and animals from foot, horseback, vehicle, or helicopter. Intermixing these balls with our Powder Ball (#5909) is an effective way to deter and monitor nuisance animals. Available in yellow, blue, and orange.