About 20 years go, my then-BIL used to breed pits and he used them for hog hunting. He gave a pup to my then-SIL, who lived with my wife and I. She was a flake and left the dog to us when she moved out. The dog was sweet, a buckskin colored female. I got another one (blue brindle male) so she could have a playmate that she couldn't just tear apart. He was great, too. One day, my sister came over and brought her 2 young kids (9 & 8 or so). Kids were running around the yard, doing kid shit. Then I see my sweet female look at my nephew in a way I'd never seen her look before. She started barking at him. Told the kids to GTFO the yard and back in the house. I never let them around a kid again and found them new homes when I decided to have kids of my own.
Both of those kids turned out to be huge losers. Maybe the dog knew what was going to happen and those barks were her way of warning them to get their shit together?