My uncle has five goats on about 20 acres of land and he lets his goats run free at night however he does lock them in a horse trailer. The reason for this is sometimes a coyote or possibly a wolf could be out stalking and maybe even some sort of wild cat.

Never the less the goats need to be safe as they are sometimes easy prey. I have always thought about getting two goats as one would get lonely but just think how much time you would save and how much better for the environment if you had a goat to eat your lawn and brush.