caterpillar that squeaks

I don't have a picture or even much of a description.

We live in central Pennsylvania.


The caterpillar is fuzzy.


I was talking to my sister and she relayed a 'funny' story about her little boy.
She said he ran into the house holding a large, fuzzy caterpillar.
He was very excited because when he squeezed it lightly it sounded like someone
playing a harmonica (badly playing it).

She said they'd never seen one like that and she was afraid of it so she made him take it back outside.

All she remembers is that it was fuzzy, large, and she had never seen one before despite growing up in and living her adult life in the country.


Any ideas what this could be? I never heard of a caterpillar that makes noise as a defense.