I had a conversation with my doc while he was snippin' and cuttin' my vas deferens about an AI (artificial insemination) hog operation. To figure out which sows are in heat, the operators put chowder chalk on the bellies of "teaser" bores (they shoot blanks), and set them loose in a pen full of sows. They come back in 15 minutes and AI the sows with chalk on their backs. We had this discussion for 15 minutes while he performed the procedure. It kept my mind off the business at hand, which was a good thing.