I usually ride the trails so that happens very little, but once (first time I ever rode since I was a kid...renting bike with "idea" of getting one at the time) while riding the Pinellas trail I saw a firecracker (just a little bobcat type) "pop" right in front of me.

Luckily, I'm not the skiddish type, so didn't even slow down. I looked from the side it came and saw 3 kids (probably around 12 years old) behind a wooden fence (saw them through cracks). And I heard one of them mutter, "Oh sh1+....he saw us. Let's get outta here.".