The Namaqua dwarf adder or spotted dwarf adder is possibly the world's smallest member of Bitis (the Vipers)
In the picture below you can see they have the typical strongly keeled scales and inhabit sandy dune environments (mostly coastal).
They appear to have evolved an adaption to high predation rates in that the breed multiple times per year, unlike their other viper counterparts.
Once again due to its very specialized and limited range, it is classed as a vulnerable species...
This "rocket scientist" pictured above is demonstrating the size if this snake for us.
However with one recorded bite, although not life threatening, it was painful, created swelling and a blister (hematoma) which lasted a couple of days... therefore not recommended good rocket science.