Trichobothria

Trichobothria are elongate sensory hairs (macrosetae) found in Arachnids. The animal can sense movement and touch by the motion of the hair in the socket in which it is set. In springtails, the presence and distribution of trichobothria is taxonomically significant. Unfortunately these hairs are easily lost, but the sockets in which they are set remain and thus can be determined even in the baldest of springtails.