:)
Try one or more of these - make sure you click on the Amazon tab at the top on NSC:-
http://www.amazon.co.uk/gp/product/B0077LW0M6/ref=oh_details_o04_s00_i00?ie=UTF8&psc=1
Have a couple of these, one in the front of the house to discourage "deposits" on the gravel strip at the front of the...