Meet The Lizard That Shoots Blood From Its Eyes — A Herpetologist Explains

Horned lizards use ocular autohemorrhaging to eject blood from their eyes as a controlled defense.

They raise pressure in eye sinuses by restricting venous outflow while arterial inflow continues.

The blood stream can reach about one meter and is usually aimed at the predator.

The blood contains compounds from harvester ants and repels canid predators in experiments.

This behavior is repeatable without apparent long-term harm and is specific to canid threats.