"slow walker" and was given by  Lazzaro Spallanzani  in 1777. The name water bear comes from the way they walk, reminiscent of a  bear 's  gait . The biggest adults may reach a body length of 1.5 millimetres (0.059 in), the smallest below 0.1 mm. Freshly hatched  larvae  may be smaller than 0.05 mm.