What sensory organs do scorpions have on their underside?

Scorpions have sensory organs called pectines on their underside. These paired, comb-like structures project from the second abdominal segment and are covered with numerous tiny sensory pegs.

Pectines help scorpions read the ground beneath them. They detect chemical traces, vibrations, texture, and other environmental signals, helping the animal navigate, locate prey, recognize potential mates, and assess suitable surfaces. Their position close to the ground makes them especially useful for a nocturnal animal that often hunts in darkness.

The name comes from the Latin pecten, meaning “comb,” a reference to their appearance. Pectines are not the same as trichobothria, which are fine sensory hairs found on the pedipalps and legs and are especially important for detecting air movement. Scorpions also possess four pairs of book lungs, but those are respiratory organs located elsewhere on the underside and should not be confused with pectines.