If you have a large Rural garden or property, then you may get many different visitors. Some are welcome, and some are not.
Whilst it may be awfully nice watching Deer or Rabbits in your garden, if they are munching their way through your prize carrots it may not be such a nice view. Badgers (who are protected) love digging up lawns and can cause a lot of damage very quickly.
Now these are situations where prevention is much better than the cure, and there are a wide range of non-lethal methods that can be employed to deter these visitors, which would include fencing or subtle changes to the garden.