Has anyone any experience of using a product called Plug-in Pest-Free? It's
a small box that plugs into a 13-amp socket and is claimed to drive away
rodents. To quote from http://www.pestfree-products.co.uk/ :

"The PestFree Plug is built around a computer chip which is ... programmed
to alter the electromagnetic field, which is produced by the mains
electricity as it flows around your wiring. This is normally 50Hz which is
perfectly acceptable to Rats, Mice etc. and Housebound insects such as
cockroaches. The change which Pest Free Plug produces in the electromagnetic
frequency disturbs the equilibrium of all household pests to such an extent
that they no longer EAT or BREED and, most importantly, try to get away from
this disturbance as quickly as possible."

It is claimed to have no effect on other electrical equipment.

The implication of the sentence which mentions 50Hz is that it alters the
mains frequency!

Is this (a) possible, and (b) safe for other equipment? And (c) does it
work?
--
Richard J.
(to e-mail me, swap uk and yon in address)