Stare at a cat long enough and you’re likely to catch them engaging in a prolonged session of blinking, closing their eyes for a brief moment before opening them. Blinking slowly is a perplexing habit, even by cat standards. Is it a form of communication? Are cats trying to express their utter disdain for humans? Do they have something in their eye?

While animal experts can’t say conclusively, the slow blink is probably a good thing. Speaking with Inverse, Mikel Delgado, a cat researcher at the University of California Davis School of Veterinary Medicine, says cats often express negative emotions by avoiding eye contact. If they’re afraid or feel threatened, they won’t stare. If they’re focused on something without blinking, chances are they’re feeling aggressive. Therefore, one way cats can hold eye contact without signaling you’re about to be attacked is to blink.

It’s not a reflexive movement, either. Cats have been observed to blink in different ways, closing their eyes rapidly and opening slowly while also closing and opening at a deliberate pace. Put another way, the cat is blinking the way it wants to.

While it may not exactly be an expression of love, it is likely a sign of contentment. If a cat is feeling comfortable around a human, closing its eyes is an indication it doesn’t need to monitor you as a possible threat.

But do cats care if we blink back? That’s harder to know, but it’s nonetheless a good way to maintain your status as a harmless human. Staring into a cat’s eyes for a prolonged period of time may be perceived as a threat.  

Theories about blinking are more a process of elimination that conclusive science, but in the absence of cat testimony, it will have to do.

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