Originally Posted by jcat
Blinking means "I mean you no harm", and is a great way to make a nervous/unknown kitty relax. When your own kitty does it, it usually means "I'm okay, you're okay!"
Exactly! It's a great form of animal communication, and very widespread. Only predators have eyes placed facing forwards rather than to the sides of the head, for focusing on prey, whereas a prey animal needs to scan a much wider area in less detail for signs of movement.
An unblinking stare from a pair of forward facing eyes is a challenge to another predator, or 'I'm hunting you' to a prey animal. So slowly blinking can be used to communicate to many animals that you are no threat to them, you are neither challenging them for territory, nor are you intending to eat them.
The slow blink works particularly well when attempting to reassure and win over small prey animals or birds that are kept as pets, parrots especially love to blink back at you once they know that your intentions are benign. It shows they trust that you will not make them your lunch