There are a number of potential dangers that could occur while bicycling, including bad or inattentive drivers, other cyclists, rough or uneven riding surfaces, broken parts, potential crime, etc. But, the danger that worries me the most often is an unprovoked attack by dog(s). Perhaps this is because two decades ago my ex-wife was attacked and bitten by a German shepherd as we pedaled past tranquil farms along a county back road in West Central Indiana. Fortunately, we found the owners and learned the dog was up-to-date on its shots.
Ever since then, I keep a wary eye and ear out for aggressive, angry, and/or dangerous dogs. There is one dog in particular who lives along my bike commuter route, who sprints up toward the trail as soon as it sees me riding past and stops just short of my position due to their invisible fence. Would it ever bust through the electronic barrier and attack me? I wish I knew the answer to that question. It is obviously not running up there and displaying a playful demeanor. My only defense at this point would be to use my helmet, back pack, or bike itself as shields. I guess I should consider other options like mace, a spray water bottle, or an umbrella to better fend off an attack.
Aside from my irritated morning greeter, most often I worry about dogs living in rural areas as they seem less likely to be controlled by leash, chain, or electronically and they seem more likely for an unprovoked attack given their exposure to wild animals and run-free conditions. To date, I fortunately have never been bitten, but it is something that remains in the back of my mind while riding.
So…what scares you the most while bicycling?