Do those electronic pest control devices work?

Yes, they do. I used one when I had a stubborn red squirrel invading my attic amd it successfully got rid of it. It wasn't ridex and it was for insects also but it worked great with the squirrel. Also, it was not one of the type that works on the wiring, instead it emitted a ultrasonic bleep that scared away pests, but didn't bother dogs or cats.

Haven't used one myself, but had bad experience with ultrasonic devices in the past. As far as Riddex is concerned, the following government site seems revealing: http://www.ftc.gov/opa/2003/07/global.shtm

I have heard that the electronic waves the devices produce opperate on the same frequency as the brains of the pests and thus they stay away. I have used one in the past and it worked great for ants, and other creepy-crawlies, but it did not help me with spiders....

properly I for one imagine those issues are ineffective.I had one and a spider became sitting good on suitable of the concern.I thrown it away and were given quite some floor spray that you want to spray everywhere in the homestead. It lasts for as a lot as 6 month.that finally were given rid of the critters. per chance you've more effective success in searching one which works.

Tried it several years ago. Did not work for me.

if it is small crawly things, Combat gel works best.

if it is mice, good old traps.