In a study, scientists used a fake leg to simulate a person stepping on a rattlesnake. Out of 175 snakes that were physically "stepped on" by the booted foot, only six bit the leg. The rest tried to get away, froze in place, or wriggled in surprise but didn't react aggressively. It's actually really hard to get bitten by a rattlesnake. They just want to be left alone.
Rattlesnakes also don't rattle before striking. A rattle doesn't mean aggression, it's an "excuse me, I'm down here." They rattle to tell you, or other large animals, that you are about to step on them, since they blend in very well with their surroundings and they'd rather you didn't smush them accidentally. Strikes are generally noise-free acts of last ditch desperation.
Only about 1% of rattlesnake bites are deadly, and those that are generally happen in situations where medical care was delayed. A quarter of rattlesnake bites don't actually involve any venom at all, they are "dry bites" intended as a warning only. As long as you get to a hospital in a reasonable amount of time, you will probably be fine. This is not a situation where minutes count, just move promptly towards medical care. The deadly bites generally happen in very remote areas, when people are hiking alone, or when drugs and alcohol are involved, since all of these can increase the amount of time it takes someone to get to help or result in poor decision-making. First aid for a bite? Just get the person to a hospital, promptly, but safely. There is nothing else you need to do, and anything you might think about doing is just wasting time getting the person to a hospital and potentially complicating things by rubbing germs into the wound or further stressing the currently stressed tissue in the area. Don't ice it, tourniquet it, or suck on it, just call 911 or start hiking back to the trailhead.
The anti-venom products ERs use are combination formulas, which work for multiple North American venomous snake species. One works for multiple species of rattlesnakes, cottonmouths, and copperheads. A second anti-venom product works for various rattlers if you know you heard a rattle but aren't sure of the exact species. Coral snake bites can be identified by looking at the bite itself by hospital staff because the venom works on the body differently and there is a separate antivenom product that works for them. All of this means you don't need to try to take a closeup picture of the snake that bit you, coax it into a box to bring with you, or kill it to bring in and show to the doctors. In the case of rattlers, copperheads, and cottonmouths, they have what they need to treat a bite without knowing exactly what species of snake it was, and in the case of coral snakes, can figure out that one bit you without seeing the snake. Don't waste time or risk a second bite messing with a snake that is already very upset.
