Horned lizards use a wide variety of means to avoid predation. At least four species are also able to squirt an aimed stream of blood from the corners of the eyes for a distance of up to five feet. They do this by restricting the blood flow leaving the head, thereby increasing blood pressure and rupturing tiny vessels around the eyelids. This not only confuses predators, but also the blood tastes foul to canine and feline predators. It appears to have no effect against predatory birds.