  We simulated random walk of rectangular particles on a square lattice with
periodic boundary conditions. Two kind of particles were investigated, viz.,
so-called `blind' and `myopic' particles. We found that steady state patterns
occurred only for some values of the ratio $L_x/L_y$ where $L_x$ and $Ly$ are
the linear sizes of the system and only for `needles', i.e., the particles of
size $1 \times k$. Different patterns were observed for `blind' and `myopic'
particles.
