Insects are able to generate impressive attachment forces but it is even more astounding that they are able to run with such sticky feet. We study how they solve the conflict between attachment and locomotion using highspeed video analysis, video microscopy, shock freezing and a variety of preparation techniques.
A general principle is that adhesive foot pads only stick when pulled toward the body, but unstick when moved away from it, allowing effortless and rapid detachment. Insects can do this actively through their claw flexor muscle but in most cases, the foot is able to attach and detach passively, without the help of any nerves and muscles!
But how then do insect feet push??
Climbing, both up and down, requires not only pulling but also pushing. We found that cockroaches solve this problem by walking on different parts of their foot. They use their "heels" when pushing and their "toes" when pulling.