  We study the behavior of skyrmions in thin films under the action of
stochastic torques arising from thermal fluctuations. We find that the Brownian
motion of skyrmions is described by a stochastic Thiele's equation and its
corresponding Fokker-Planck equation. The resulting Fokker-Planck equation is
recognized as the one for a high-friction Brownian particle which has been
studied extensively in different physical contexts. It is shown that thermal
fluctuations favor the skyrmion motion allowing a finite mobility even in
presence of pinning traps. We calculate explicitly the mobility tensor of
skyrmions in linear response to an electric current finding that it increases
with temperature.
