LOL!...I can identify with that. Our Buck Creek Trails system is directly next door to our city's police academy which has a large range for pistol, rifle, and tactical training. You really get used to the pistol and rifle fire, but once in awhile someone breaks out a Barrett 50 cal, and the first shot will definitely make you jump.
On rattlesnakes?...we got 'em in droves out here. Since we built that trail system starting in 1999, I can't count how many rattlers I've run over during the years...but with no adverse effect...at least to me.

In all these years, we've only had one rider bitten, and he was foolishly off trail pushing his bike through tall, dry grass to jump to another trail...don't worry, he lived and still rides. No one has ever really come close to being bitten while on the trail surprisingly. Horror stories about rattlesnakes are usually wildly overexaggerated.
The other critters out there such as feral hogs, armadillos, coyotes, skunks, and deer have never caused any rider any harm. The danger from feral hogs, like rattlesnakes, is highly exaggerated too. They run like scalded dogs when they see or hear you coming. Oddly, the armadillos may be the most dangerous, as they wait until the last second to come bounding out of the brush right in front of you. They're blind as a bat, and their football sized body armor structure can make you go down if they get your front wheel. Again, no one ever injured that I know of. It's wild kingdom out there, I tell ya.