This video shows how a chironomid (midge) larva undulates in its tube to circulate water to aid in respiration. This particular genus (Cricotopus) builds a portable tube, while other chironomid groups construct more extensive stationary tubes in the mud. The video also shows how chironomid larva that build portable tubes move by reaching out and pulling themselves forward. In the final scene, the midge larva gets caught on a strand of vegetation and uses a small pebble to leverage itself up and over.