Avajoy,

Have you had your windows open while it was plugged in? We have had our latest plugged in for about a month now and it is still about 1/3 full. The first one we used lasted about a month. We have found it makes a pretty definate difference in the aggressiveness of our cats to one another. They still don't particulary want to sleep together but they aren't out for blood anymore either. But if you get a reply from the company let me know what they said...I would be very interested.

Denyce