Figure 5. Swimming and crawling worms maintain a constant turning rate by distinct means. (A) Moving worms change their heading principally by using omega bends (i) and reversals (ii). (B) Body curvature matrix showing a ten second period during which a swimming worm performed an omega bend resulting in a change in heading (arrowhead). (C) Curvature matrix showing a crawling worm performing a reversal resulting in a change in heading. In the plots blue, white and red denote body angles of 50, 0 and -50 degrees respectively, a means anterior and p posterior. (D) On land, worms used mostly reversals to change heading (i) while in water, the use of omega bends predominated (ii). Interestingly, the rate at which the animals turned remained constant in both environments (iii).