I too purchased three of the Bell and Howell Animal repeller and charged the batteries as instructed. I placed the units on my front yard grass and watched to see if dogs or other animals had any reaction. NONE. The dogs came to take their customary pee and like the B&H Animal Repeller so much they came up to them to sniff them. THEY DONT WORK EVEN IF THE LIGHTS COME ON. The lights come on in all three of my units but they DON'T REPELL THE ANIMALS.