Don't freak out. Boys are boys! Many of them have an insatiable need to push themselves, test their limits, and scare the snot out of mom all at the same time. It's a flexing-their-muscles thing!
There's a watchful eye on their overall safety, but then there's hovering and fussing. Are you a hoverer? And how can you tell the difference between a watchful eye and a hovering fear?
I've often had to ask myself, "What's the worst that could happen?" And yes, the worst that could happen might be death. But then, if I'm so concerned about the possibility of death, I wouldn't put them in a car, with or without a seatbelt.
Or a bathtub. Or feed them shellfish because they *might* be allergic and go into anaphylactic shock. Or allow them to plug the vacuum into the outlet because it might electrocute them. Or let them cook anything on the stove.
See? There's a general view of safety and common sense (I wouldn't hand a two-year-old a hunting knife), and then there's allowing them the freedom to climb the highest tree in your neighborhood, touch the slimiest bug in your yard, and longboard down the steepest hill they can find.
Scabs? Broken bones? Those are medals of honor.