Assertion: snake | /r/Desires | concertina locomotion
Facets:
Source sentences:
text: When push-points are absent, but there is not enough space to use sidewinding because of lateral constraints, such as in tunnels, snakes rely on concertina locomotion.
text: When push-points are absent, but the space is too narrow for sidewinding, such as in tunnels, snakes rely on concertina locomotion.