what I learned about copperheads

Copperheads are the least toxic of the venomous snakes and their bites are rarely fatal.  

Copperhead venom is not a neurotoxin but a hemotoxin which attacks the red blood cells and breaks them down to prevent clotting.

The anti-venom is extremely dangerous (which is why they would have had to put me in intensive care to administer it).

Unlike other snakes that display a body posture as a warning, a copperhead's warning is to strike.

Unless they are hunting, they control the amount of venom injected.   A copperhead has no intention of wasting valuable venom if it can scare away the menace with a minor bite.  (Lucky for me since even that small amount caused my entire leg to swell up about double normal and has been very painful.)

Effects of  a copperhead bite include intense pain, swelling, nausea, thirst, discoloration of the skin, weakness, low blood pressure, destruction of tissue. (I experienced most all of those except the low blood pressure and, I hope, the destruction of tissue.)

For a healthy human adult it takes about 10 - 14 days to fully recover from a copperhead bite.

Their main source of food is small rodents but they will eat other reptiles and amphibians.

Copperheads shed their skin 1 - 3 times a year.

Females reach sexual maturity after about 4 years and give live birth to 3 - 10 babies.  Young snakes are 8 - 10", adults are 20 - 40".  (My best estimate of the one that bit me is about 20".)

They winter over in dens sometimes with other snakes and are most aggressive in spring during mating season.

Copperheads and the common rat snake are very hard to tell apart by their coloring and markings.  The pupils of their eyes, however, are very different.  A copperhead has a slotted pupil like a cat.  A rat snake has a round pupil like a human.  Also, rat snakes don't have fangs, their bite is more like a human bite (so that sort of clinches it since the snake that bit me definitely had fangs).