Zebras have bold stripes to protect them from being attacked, according to new research from Australia.
University of Queensland scientists say the black and white patterns work by dazzling and confusing predators, especially when zebras move as a herd.
Scientists analysed photos and video footage of zebras to test the theory.
Research in the past has suggested the stripes were used for camouflage in grassy habitats, as a way to communicate, and even to control heat.
Using computer models, researchers showed that the markings make optical illusions when the animals move, making it hard for predators to focus on individual animals.
The stripes don't just confuse big predators like lions - biting insects like mosquitoes are affected too.
The research was published in the scientific journal Nature.