Take one 3 litre Coke bottle (or similar).
Drink or otherwise dispose of contents.
Remove cap and blow across the top.
Make sure your blowing creates a beautifully modulated, deep, soulful, resonant, dirge-like sound.
You now have your own environmentally friendly Dog Annoyer. The sound can be used to irritate dogs up to half a mile away, inciting a chorus of vengeful barking to warm the heart of even the most jaded of cats.
Health and Safety notice:
Your Dog Annoyer should not be used within attack range of a dog, and not used at all unless you have checked your catflap is lockable.
Younger cats should seek the help of an adult.
Wholesome Socks cannot accept reponsbility for any woe. I am totally irresponsible.
Roobarb and Custard.