  We describe the curves of constant (geodesic) curvature and torsion in the
three-dimensional round sphere. These curves are the trajectory of a point
whose motion is the superposition of two circular motions in orthogonal planes.
The global behavior may be periodic or the curve may be dense in a Clifford
torus embedded in the three-sphere. This behavior is very different from that
of helices in three-dimensional Euclidean space, which also have constant
curvature and torsion.
