We'd heard of putting tennis balls in a clothes dryer before--apparently the spheres create air pockets in the tumbling mess that help laundry dry quicker--but we'd never heard of a non-sports use for golf balls, let alone a farm-related one, until now.
Apparently farmers in Australia put golf balls under brooding hens, because the sensation of sitting atop something egg-like keeps them happy while they're not conceiving. But in New South Wales, an interloping carpet python had "got in thinking that he has got a free meal and swallowed up these four golf balls." The snake was x-rayed and the golf balls were surgically removed. (Which leads us to wonder, how do snakes, particularly carpet pythons, convalesce? Do they stretch them out on a Slip-n-Slide and cover them with a long blanket?)
And in case you haven't yet seen this video, here's another odd use for a tennis ball: