How to Identify the Rhombic Night Adder (Identification Guide)

Key identifying features

The Rhombic Night Adder is identified by a series of dark, diamond or rhombus-shaped blotches running down its back, combined with a distinctive dark V- or chevron-shaped marking on top of the head. This head marking, paired with the rhombic body pattern, gives the species its common name and is the most reliable field mark.

Coloration & pattern

Base color is usually olive, grey-brown, or tan. Along the spine runs a series of dark brown to black rhombic (diamond-shaped) blotches, often with lighter edges, spaced somewhat evenly down the length of the body. The flanks may show smaller, less regular dark spots between the main dorsal blotches. The belly is pale, sometimes with light speckling.

Head, eyes & scales

The head is moderately broad and only slightly distinct from the neck, bearing a dark V-shaped or chevron marking on the crown that points forward toward the snout. Eyes are moderate in size with round pupils, distinguishing it visually from the vertically elliptical pupils of many other vipers. Scales are keeled, giving a somewhat rough texture.

Size & body shape

This is a moderately stout, medium-length snake, thicker-bodied than typical colubrids but less massive than large vipers such as the puff adder or Gaboon vipers. The tail is short and tapers quickly.

Range & habitat where you'll see it

Widely distributed across sub-Saharan Africa, the Rhombic Night Adder favors grassland, savanna, and areas near water such as marshes, ponds, and riverbanks, reflecting its diet that includes amphibians. It is primarily active at night or during twilight hours, though it may also be encountered during the day near water sources.

How to tell it apart from look-alikes

The round pupils are an important distinguishing trait separating it visually from most other vipers in its range, which typically show vertical pupils. Its rhombic blotch pattern and distinctive head V-marking further separate it from the puff adder's chevron banding and from other night adder species, which may show subtler or differently shaped dorsal markings.