I've had one ferret for a year and one since Christmas. They have run of my two-bedroom condo unit. The fleas have gotten progressively worse. Over a week ago I went on a week's vacation and took them with me. Right before I left I bathed them with a flea shampoo and then used a spray to kill any that missed. They were flea free until I got back. After 1.5 hours I checked the ferrets and each probably had 15 or so fleas. Last Wednesday I went to my vet and got Advantage (after signing a disclaimer that I knew I was using an untested (on ferrets) product). I put it on (used half a tube on each ferret) at 9:30am and when I got back home at 8pm all fleas were gone, and I even found a couple dead ones in the fur. This morning one of my ferrets had a couple fleas, but she just woke up and might not have been there long. I used a spray to get them, but I should have left them to see if still there tonight. Larry [Posted in FML issue 1670]