We had an epidemic of copperheads around here a few years ago. When the point came that my wife became afraid to let the grandkids go out and play, I began hunting them down at night. Some nights, I'd get as many as five, other nights, maybe just one or two, but it was rare to not see any at all. That went on for five summers before I finally made enough of a dent to feel perty-safe in slacking off for a while.
Like I said, that was a few years ago. These days, I'm only seeing one or two a year. On the other hand, you can bet the farm that if you see one, there's more that you aint seen....so...it won't be long until I'll be back to thinning them out again.
DGW