Pilomotor reflex wani martani ne mai jujjuyawar guraben gashi zuwa abubuwan motsa jiki kamar sanyi, tsoro, ko damuwa, wanda ke sa gashin ya tsaya a ƙarshe. Wannan reflex yana faruwa ne ta hanyar raguwar ƙananan tsokoki a gindin kowane ƙwayar gashi, wanda aka sani da tsokoki na arrector pili. Kalmar “pilomotor” ta haɗu da “pilo-” daga kalmar Helenanci don gashi da kuma “-motor” ma’ana motsi, yayin da “reflex” yana nufin amsa da ba da son rai ga abin ƙarfafawa.