Consider the third example:

The states of the sheep at zero seconds.

\begin{center}
  \includegraphics[scale=0.75]{sheep-move-border.1}
\end{center}

The state of the sheep at one second.

\begin{center}
  \includegraphics[scale=0.75]{sheep-move-border.2}
\end{center}

Trimmed the field to $4$ cells.

\begin{center}
  \includegraphics[scale=0.75]{sheep-move-border.3}
\end{center}

The state of the sheep at two seconds.

\begin{center}
  \includegraphics[scale=0.75]{sheep-move-border.4}
\end{center}