the common night adder is a fairly fast species of snake; it can move at the speed of 3.3 km per hour. they are usually found on the ground, but they can climb trees and can swim. they are mainly nocturnal, but some have been seen basking in the early morning or late afternoon. when disturbed they coil up, inflate their body (which makes the black blotches on them stand out), and start hissing loudly.