Most of small organisms interact with fluid in nature. Such dynamics of soft bodies interacting with fluid is complicated, highly nonlinear, and important for understanding many problems arising in biology.
For example, a nematode lives in various complex environments such as crawling on a agar plate, swimming in fluid, swimming in a capillary tube, swimming in a wet granular medium, and often interacting with each other. We're also interested in other organisms swimming in various fluidic environments.
Permalink: Dynamics of Soft Bodies