Springtails look chaotic to the untrained eye. Whether on a balmy pond or melting snow, the miniscule creatures are, true to their name, constantly springing up from the surface in a cloud of microscopic mayhem. Despite appearances, a study led by Victor Ortega Jiménez, assistant professor of integrative avian biology and biomechanics at the University of Maine School of Biology and Ecology, has found that the aquatic springtails’ pattern of jumping, soaring and landing is not a disorganized dance, but a perfectly choreographed aerial ballet that is fundamental to their survival.
Springtails are the largest group of six-legged creatures that are not insects (they were once considered insects, but have since been categorized separately as Collembola because they have soft bodies, no wings and hidden mouthparts). They are known for the unique parts of their bodies used for jumping and adhering to landing surfaces, known as the furcula and collophore, respectively. Previously, biologists assumed that the critters couldn’t control their explosive takeoff, tumultuous midair spinning and landing.
Turns out, those funny appendages make springtails into nature’s precision strike missiles. Springtails use the furcula to their body angle and the speed during takeoff, as well as the angle of the body posture in midair. Then, they use the water-loving properties of their collophore to achieve a near-perfect landing, touching down on their undersides nearly 85% of the time and anchoring to avoid bouncing.
Jiménez, head of the Ornithopterus Lab, led the project while at Georgia Tech with researchers the Bhamla Lab and the Koh Lab at Ajou University in South Korea. They used mathematical modeling to show how the appendages influence the springtails’ launch, flight and landing. Through their models, they were also able to show that springtails can curve their bodies to form a U-shape pose that leverages aerodynamic forces to right themselves in less than 20 milliseconds — the fastest ever measured in animals.
“Springtails were portrayed as uncontrollable jumpers. We discovered that these arthropods that have no wings and are smaller than a sand grain are able to control their jumping direction, skydive and land on their feet, in less than a blink of an eye,” says Ortega Jiménez.
The researchers at the Koh Lab also designed a jumping robot inspired by the biophysical principles of the springtail. The robot was able to reduce in-flight rotation and land upright about 75 percent of the time.
“This jumping robot, which uses drag enhancers and an extra weight, can right itself in midair and land ventrally most of the time, in a similar way as springtails. This simple mechanism can be used to enhance a safe and upright landing in any robot or device that catapults explosively in the air,” says Ortega Jiménez.
The study was published Nov. 7, 2022, in the Proceedings of the National Academy of Sciences.