Some property managers need to kill them to keep control of the environment. But killing too many can be bad as well. Snakes manage rodent populatons.

Just a side note. Last week while playing frisbee golf on a local Northern California brewery's property, my buddies and I came upon the littlest baby rattler staking out an ant hole. It was maybe 8-10 inches long. We simply played through but it was cool to come upon it.