Cat Deterrents

Cats have always been a problem in our garden - harassing and killing birds, killing fish and fouling the garden - but then in the 1990s, when nearly twenty different cats were intruding we decided something had to be done.

We tried various deterrents that others had recommended, these included:

• Clear glass bottles filled with water and shiny metal foil on string to create reflections that disturb the cats. These had had no effect whatsoever.
• Cat pepper and ammonia, but these do not last very long in our wet climate.
• Sharp, thorny clippings, e.g. holly and blackthorn, on the ground to stop them walking and fouling the area. This does work but the garden can become unsightly with clippings all over the place.
• Electronic units that detect movement and either emit an ultrasonic noise or fire a water jet.

One suggestion we did not try, for obvious reasons, was having our own cat to defend the garden from other cats.

Ultrasonic Scaring Devices

Although sceptical about the likely success of the electronic cat scaring devices we purchased a Catwatch MkII from Concept Research.

This small device (shown on the right) emits bursts of ultrasound when the integral movement sensor detects something moving.

The only specific problem we have experienced with the Catwatch MkII, of which we have three units, is that the exterior of the lens has a tendency to mist up with frost or dew and stop working until it clears. Also, this lens becomes brittle with age, but replacements are available from the supplier.

The Scatter unit, shown on the left, does not have a movement sensor. Instead it emits ultrasonic bursts of random duration at random intervals. Consequently, this unit's performance seems unaffected by weather conditions.

The Scatter unit was available from Krystal, but the company seems to have either ceased trading as Krystal (or Clearflow) or ceased all together.

Both types of unit work! Most cats are stopped in their tracks before making a rapid departure, while other more welcome wildlife such as foxes, bats, and hedgehogs seemed not to be affected. Today, there are just two or three cats that visit the garden and we presume they are either deaf or daft!

As well as deterring the cats, you can protect the birds by ensuring they have cover such as a tree or bush close to where they are feeding, but not so close as to provide a hiding place for cats and other predators.

There are other similar systems available, such as CatStop from Electric Fencing Direct.