I know that mountain lions have attacked in my residential area (well in parks surrounded by residential areas). In one, in the 80's, a mountain lion grabbed a six year old girl and mauled her before she was released, while she was walking through Casper's Regional park with her parents. Photos later developed showed the cat stalking the child as the family walked - in the bushes beside them. In another, a woman was attacked and a man eaten in Whiting Ranch which is surrounded on three sides by residential areas.
In another, not too long ago, in LA County, I believe by Griffith Park Observatory, a man camped by himself and slept in sleeping bag. A lion came up and sniffed him and tried to bite his head.
The mountain lions in the zoo at Irvine park are totally fixated and stalk and pace back and forth while staring at any toddler or baby in a stroller that comes near their enclosure. It is obvious they want to eat them. I know that wolves are scared of humans but there have been several cases in Idaho where they will not leave the animals they are stalking despite hunting humans who arrive with guns and dogs, and will keep coming back to the prey even when they are shot at.
Finally, just last May a coyote attacked and bit a toddler at Irvine Park near my home, which is bordered by a toll road, residences and canyons.
Most wild animals shy from humans but small humans are simply prey to them. No different than any small animal. If they are hungry enough, they will track a small child and attack.
The lack of blood droplets though or any torn clothing does point away from such an attack.