We have 6 horses, 3 goats, and an endless population of FLIES!! We've tried EVERYTHING...and this is by far the best product yet! We have been reusing the gallon container, and it collects an amazing volume of flies in just a couple of days. Clearly noticing less flies around the barn, on the horses, etc. And we like that it isn't a poison..so while we keep it from our dogs, it's not as much risk to them. We bought both the gallon and quart size containers, though found the quart lid didn't fit well. So highly recommend the gallon container - then simply buy the refills and watch them die by the thousands....maybe even tens of thousands!