The Riddex pest repeller produces high-frequency sound waves that are harmless to humans and pets (except rodents), but which are heard by insects and rodents and are supposed to drive them...
It doesn't. The FTC has info on these scams at http://www.ftc.gov/opa/2001/05/fyi0128.shtm. Enter "Pest Repeller" in the FTC search window for more info.
I can answer this easily with a resounding NO!!!! I had an aunt that invested in this type of pest control for fleas and mice and it simply did not work.