I went with squirrels because they ALWAYS jump out onto the path right in front of me. I rarely see kids on the path here. Really, though, my greatest fear is definitely bicyclists going the other way. The path has a few nasty turns downhill and I could easily imagine a situation where somebody doesn't quite stay on their side or doesn't even see it coming if they're not paying attention to the one sign that warns them. Thankfully I haven't yet passed by anyone in a turn yet.