We have had close to four dozen copperheads in or within a few feet of our yard in a month. We suspect they're after insects.
The yard is not very big, so the snakes are a hazard. Also, as you probably guessed, the house is in the country.
Thanks in advance for your advice for how to deal with this problem.
Snakes follow habitat. Control the habitat and the snakes will be controlled too.
Cut the grass, remove wood/brush/stone piles, and other structures that provide "cover".
Copperheads do eat cicada but their diet focuses on rodents, frogs, and similar sized creatures. You can also put up a drift fence to direct snakes away from an area that you wish to protect. Visit http://icwdm.org for info on the drift fence.