source of your cat's purring has been a bit of a mystery for scientists.
Why cat's purr and how they purr has been long debated. Initially it was
thought cats might have a 'purring organ', although it is now generally
agreed a cat's purr comes from a vibration in the cat's trachea connected
with its breathing. Purring is a voluntary reaction, so the next question
is, why do cats purr. Happiness or contentment is the most common reason
for a cat to purr. However, cats also purr when highly stressed, injured,
or giving birth, clouding the exact reason for purring. While scientifically
unproven, some believe a cat's purr may have a healing quality associated
with its sound frequency. It has also been thought that purring is a way
for a cat to connect with others. House cats are not the only ones to purr.
Pumas, Cougars, and Bobcats also purr. In determining whether a cat can
purr, the general rule is if a cat can roar it can't purr. Oddly enough
raccoons have also been known to purr. Like many of the actions of your
cat, it may be the only one to truly know why it purrs.