In my younger years, the backfire in the country would usually send horses running when they were in a field (never with people riding them). And I found out that dogs would squat and cats would jump straight up in the air and run.
I guess I was as bad as the kids today doing the "Train Horn Prank". Believe it or not, I have grown out of that (and don't want to pay for fixing the muffler!!!)
You can believe that I have NEVER backfired my present M-715. Mufflers are expensive and scarce.