Almost all mammals perceive direct eye contact as a threat or provocation. Humans are a very rare exception from this rule and it often creates problems in their interactions with animals. The reasons lie in evolution:
- Almost all predators have their eyes on the front of their skull to have better spacial vision. They fixate their prey with both eyes right before trying to kill it.
- Almost all herbivores have their eyes on both sides of the skull to see more of their surrounding at once. They are physically incapable of staring at anyone with both eyes like a predator does.
- Humans are both predators and very social. They express emotions mostly with the face, so looking directly at each other is nessecary to understand non-verbal communication.
This fundamental meaning of being stared at is so deeply ingrained into nature that some animals have a better chance of survival because of patterns that resemble eyes on their bodies. (For example the spots on the wings of peacock butterflies or on the head of spectacled cobras)
Staring any halfway intelligent animal directly into the eyes for a prolonged time will always create suspicion, stress, fear or provoke an attack.