>I've found that ferrets have at least 2 different types of hissing that
>they do.  When they are angry, it's a steady SSSSSSSSSSSSSSSSSSSSS
>sound.  Sounds like a leaky tire or something.  One of our previous
>ferrets, Pooh, also had a hiss that sounded like hhhh hhhh hhhh hhhh.
>It came in little short bursts and sort of sounded like panting.  He
>did that when he was happy.
 
The first is a hiss
 
The second is laughter, not a hiss.
 
Both are very ancient animal sounds, just as purring and growling are.
[Posted in FML issue 5152]