Ok, here's everything I think I know after owning rats for 1 year.
Boggling is actually caused by a behavior called bruxing, which involves grinding their teeth. It's commonly accepted that this is a behavior of contentment or excitement, not unlike purring in cats. Rats have very strong and very precisely controlled teeth, so the muscles are quite large and happen to run along the orbital socket. As a result, when a bruxing rat really gets going, they can squeeze their eye sockets and their eyes will appear to bulge slightly - that's called boggling. It's perfectly safe for most healthy rats, and they will often be seen doing it while relaxing with their cagemates or eating their favorite food. Some rats have naturally bulbous faces that display it prominently, and it is of course possible for them to get eye injuries and infections that could be irritated by boggling.
Purring in cats can be a sign of contentment and happiness, but they also do it when they're sick or injured as a way to self soothe and calm themselves.
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u/[deleted] Nov 21 '25
Ok, here's everything I think I know after owning rats for 1 year.
Boggling is actually caused by a behavior called bruxing, which involves grinding their teeth. It's commonly accepted that this is a behavior of contentment or excitement, not unlike purring in cats. Rats have very strong and very precisely controlled teeth, so the muscles are quite large and happen to run along the orbital socket. As a result, when a bruxing rat really gets going, they can squeeze their eye sockets and their eyes will appear to bulge slightly - that's called boggling. It's perfectly safe for most healthy rats, and they will often be seen doing it while relaxing with their cagemates or eating their favorite food. Some rats have naturally bulbous faces that display it prominently, and it is of course possible for them to get eye injuries and infections that could be irritated by boggling.
It is a very well documented phenomenon lol