My goodness.  Last year I purchased two of the units that hold these sticky disks.  These Ultimate Flea Trap units come with a night light and plug in and you keep them plugged in 24/7.  The unit comes with 3 disks.  After that you buy the night lights as they burn out and purchase refill disks.  I'll tell you what!  The sticky disks have not only the stickiness of fly paper, but the instructions say there is an aroma that attracts insects.  We purchased them originally because last year was a terrible year for fleas and our poor dog was bringing them in every time he went outside.  We live on a farm and every time we went out and back in, our pant legs would bring in fleas.  Terrible.  I couldn't keep fleas out of our carpet, or floor.  After buying this product and placing them on the floor from one end to the other in the living/dining areas (and putting Frontline plus on the dog) you would be shocked at the number of little fleas that get caught on that paper!  Not only that, but in the night time it has caught crickets, house flyies, stink bugs, and a couple spiders.  It's amazing and I think you will not be disappointed if you tried these refills for your Ultimate flea trap unit which is made by the same company.  If I had trouble in every room of the house, I would have a trap in every room.  I purchased one for my daughter as well and she loves hers too.