Tom
Ask John who turned him onto those calls
He didn't believe me when I told him how they work when you hit it right, but when you do they'll run right up your leg if your not careful.
They are sold as "Mr. Squirrel" squirrel call. Used to get em at Wally's. Read the back and follow the instructions, thrash a small tree around, the more noise the better. A buddy of mine in Northern IN told me about these 7 or 8 years ago and I thought he'd been tipping the jug a little. I picked one up and couldn't believe the results.
Have had grays bark at me when calling, but never had one come in like the fox squirrels do.
Have called in several hawks and owls, crows all the time, two coyotes and a red fox. These calls are a blast!
Big fun was having John's older brother Art hold his little rat terrier in his arms while I called, then shooting the squirrel with a blunt and releasing the dog. If the squirrel was not killed outright the dog would tree the squirrel for follow up shot. That there is redneck good times!
The only downside is you call a VERY high percentage of female squirrels in. Be careful early in the season or you can orphan little ones.
R