Ovoviviparous – an animal that keeps its fertilized eggs inside the body while the embryo develops. The offspring hatch and leave the body at the same time.
Pit vipers – snakes that have holes, or pits, behind their nostrils that can sense heat. This helps them to discriminate between possible prey, which would be warm, and a non-living object, such as a rock.
Jacobson’s organ (also called vomeronasal organ) – an organ of chemoreception that is part of the olfactory system (sense of smell). It is very well developed in snakes and helps them hunt and track their prey
Female copperheads in captivity can sometimes reproduce asexually (without a male).