Horn Worm Squeaks?

Hi,

My cat dragged in a tomato horn worm from the garden and the worm was
making squeaking sounds, and it's the first I've ever heard a hornworm
or any other worm or caterpillar make any kind of sound at all.

Some pictures:

http://web2.airmail.net/~elo/jpg/hornworm1.jpg
http://web2.airmail.net/~elo/jpg/hornworm2.jpg

As you can see, the hornworm wasn't completely green as most
of them I've seen in the past.  It was a reddish color, and makes
a squeaking sound when I or my cat squeezes it.  Something new
for me anyway.

Maybe they all squeak at a certain stage of development, and I
happened to catch this one in that stage.

-- 
Elroy Willis
EAP Chief Editor and Newshound
http://web2.airmail.net/~elo/news