Instruct: Classify Amazon reviews into positive or negative sentiment
Query: works terrific

I've used these for 4 years. Just can't seem to get rid of fleas, but these work great. I use a few of them as I open my windows and no matter how tiny the holes in your screens are, they get in and also come in on my family as well. They work better at night when the house is dark as fleas tend to gravitate to the light. It's amazing how many they catch, one refill lasts a very long time as the surface is large compared to the size of a flea and it remains sticky. The only other alternative would be to bring my chickens in to take care of the problem, but then there's a different problem to deal with. If my town zoning law allowed my chickens to wander, my flea and tick problem would virtually disappear.