[pfflier]

She said "circling". Hail cannons placed around an orchard would each fire on a fixed period and several would be dispersed around an orchard.

Locally farmers use propane cannons to scare birds from newly seeded fields. For a day or two it sounds like downtown Baghdad.

[Ken H]

Or Chicago.

[Jed Eckert]

I think you nailed it. I'm familiar with the propane cannons to scare birds off the crops but I must admit the hail cannon was new to me. Had to look that one up. Learn something new here every day.