the screaming pigs

No, that's not the name of a new rock band. It's the sound I listened to this morning as I sat on our back porch and drank my morning coffee. A group of boys were herding several pigs down the street that runs alongside our townhouse complex. The sound was something between a car that won't start and nails on a chalk board. Whoever coined the term "squeal of delight" was definitely not listening to a group of hogs - if so something like "grunt of fear and anguish" would have been more appropriate.