Crotalus is the group of reptiles that includes all rattlesnakes. The rattlesnakes place in American culture is solidified and they appear on numerous flags and banners going back through American history all the way to the revolutionary war.
Despite their reputation rattlesnakes are usually very shy and peaceful. They will make every effort not to attack. They will retreat whenever possible and will then give their well-known audible warning and even bite without injecting venom in an attempt to be left undisturbed. However if they feel cornered, hurt or threatened they will attack. When they attack they will strike and inject their venom and continue to do so until the threat subsides.
The correlation to this and self-defense is apparent. Never seek a violent conflict. Never go looking for a violent encounter. But if you or your loved ones find yourself cornered or facing an imminent threat of severe bodily harm (or worse), strike. Fight with everything you’ve got, using all means and training at your disposal. Don’t be a victim.