  We study FASER and FASER 2 sensitivities to the quirk signal by simulating
the motions of quirks that are travelling through several infrastructures from
the ATLAS interaction point to the FASER (2) detector. The ionization energy
losses for a charged quirk travelling in different materials are treated
carefully. We calculate the expected numbers of quirk events that can reach the
FASER (2) detector for an integrated luminosity of 150 (3000) fb$^{-1}$.
Scenarios for quirks with four different quantum numbers, and different masses
and confinement scales are studied.
